• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.5
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• pp.249-258
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• 2022

The specific muscular structure of the tongue greatly affects margin shrinkage and tumor invasion, making the optimal surgical margin controversial. This study investigated surgical margin correlated prognosis of TSCC (tongue squamous cell carcinoma) according to margin location and its value, and the histopathologic factors which are suggestive of tumor invasion. And we would like to propose defining of the surgical margin for TSCC via prognosis according to location and margin values. We reviewed 45 patients diagnosed with TSCC who visited Seoul National University Dental Hospital (SNUDH) (Seoul, Republic of Korea) from 2010 to 2019, who were managed by a single surgical team. Patient clinical and pathological data of patients were retrospectively reviewed, and in 36 out of 45 patients, the pathologic parameters including the worst pattern of invasion (WPOI) and tumor budding were investigated via diagnostic histopathology slide reading. When standardized with as 0.25 cm anterior margins, as 0.35 cm deep margin, there was no significant difference in disease specific survival (DSS) or loco-regional recurrence-free survival (LRFS). Additionally, there was a non-significant difference in DSS and LRFS at the nearest margin of 0.35 cm (P_DSS=0.276, P_LRFS=0.162). Aggressive WPOI and high tumor budding showed lower survival and recurrence-free survival, and there were significant differences in close margin and involved margin frequencies. In TSCC, the value and location of the surgical margin did not have a significant relationship with prognosis, but WPOI and tumor budding suggesting the pattern of muscle invasion affected survival and recurrence-free survival. WPOI and tumor budding should be considered when setting an optimal surgical margin.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.57-78
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• 2022

The disc cutter and cutterbit, which are the most important factors to increase the excavation efficiency of TBM, are key factors in the design and construction of the cutter head. The arrangement, spacing, number, size, and material of disc cutters suitable for the ground conditions determine the success or failure of TBM construction. The disc cutter, which is a representative consumable part in TBM construction, can cause enormous disruption to the construction cost as well as the construction cost unless accurate prediction of wear and replacement cycle is accompanied. Therefore, in this study, the method of calculating the replacement cycle of the disc cutter calculated at the time of design for the slurry shield TBM field, and the depth of wear and replacement location of the disc cutter that occurred during actual construction were compared by analyzing the field data. For a quantitative comparison, weathered soil/weathered rock, soft rock, and hard rock were classified according to the ground in the section showing constant excavation data, and the trajectory of circle was different depending on the location of the disc cutter, so it was compared and analyzed.

• Journal of Korea Water Resources Association
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• v.55 no.5
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• pp.321-331
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• 2022

In this study, we tried to present a method for calculating the amount of regression using a watershed modeling method that can simulate the hydrological mechanism of water balance analysis and agricultural water based on watershed unit. Using the soil water assessment tool (SWAT), a watershed water balance analysis was conducted considering the simulation of paddy fields for the Manbongcheon Standard Basin (97.34 km²), which is a representative agricultural area of the Yeongsan river basin. Before evaluating return flow, the SWAT was calibrated and validated using the daily streamflow observation data at Naju streamflow gauge station (NJ). The coefficient of determination (R²), Nash-Sutcliffe Efficiency (NSE), Root-Mean-Square Error (RMSE) of NJ were 0.73, 0.70, 0.64 mm/day. Based on the calibration results for three years (2015-2017), the quick return flow and the return rate compared to the water supply amount for the irrigation period (April 1 to September 30) were calculated, and the average return flow rate was 53.4%. The proposed method of this study may be used as foundation data to optimal agricultural water supply plan for rational watershed management.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.1-13
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• 2020

Tencent is an internet-based entertainment platform corporation using technology to enrich the lives of Tencent platform users and assist the contents expansion. Since 2000, Tencent have developed a great growth and innovation in entertainment contents domain. Tencent have become the market leading innovator due to the imitative innovation and M&A. The present study designed case study analyses to investigate the mechanism with regard to the growth strategy of Tencent corporation. Tencent began with imitative internet-based game and social messaging services but then added its own wechat messenger platform, now being extended to other products or services. This imitative innovation strategy enabled Tencent corporation to grow rapidly, to achieve outstanding growth. In addition, Tencent's M&A investment drive is underpinned by a vision of top management team and flexible organizational culture, from building out the Tencent's entertainment platform, game, finance, e-commerce, to global market expansion. While our results shed light on the implications to understanding Tencent's growth, there are limitations of the current study that should be considered when designing next research.

• Journal of The Korean Association For Science Education
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• v.42 no.5
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• pp.525-542
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• 2022

The purpose of this study is to comparatively analyze the internal and external frameworks of elementary science textbooks, which first appeared as the authorization system of elementary science textbooks changed from the national government system. In order to confirm the purpose of the authorization system to support the development of diverse and creative textbooks, this study compared 7 authorized textbooks with the national textbook developed as the 'Use of Magnets' unit of the 2015 revised science curriculum. In this study, the textbook's framework was largely divided into an external framework and an internal framework for the 'Use of Magnets' unit of elementary science textbooks, and quantitative and qualitative analyses were conducted in parallel according to each subcategory. According to the research results, in the external framework of textbook units, all textbooks had the same structure: unit introduction, scientific inquiry, creative convergence, unit arrangement, and scientific reading materials. The framework in the 'Use of Magnets' unit of the 7 types of authorized textbooks was found to have some differences according to the textbook development team's interpretation of the curriculum achievement standards and many commonalities that maintained the framework in the national textbooks. In addition, the characteristics of each textbook were clearly revealed in some areas not specified in curriculum such as unit introduction activities and science reading materials, a meaningful change was also found in that the level of inquiry activity was classified and operated in response to the uniform inquiry activity operation of the existing government textbooks.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.403-421
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• 2021

Most of the urban tunnels in Korea, which are represented by the 1st to 3rd subways, use the drainage tunnel by NATM. Recently, when a construction project that actively utilizes large-scale urban space is promoted, negative effects that do not conform to the existing empirical rules of urban tunnels may occur. In particular, there is a high possibility that groundwater fluctuations and hydrodynamic behavior will occur owing to the practice of tunnel technology in Korea, which has mainly applied the drainage tunnel. In order to solve the problem of the drainage tunnel, attempts are being made to control groundwater fluctuations. For this, the establishment of tunnel groundwater management standard concept and the analysis of the tunnel hydraulic behavior were performed. To prevent the problem of groundwater fluctuations caused by the construction of large-scale tunnels in urban areas, it was suggested that the conceptual transformation of the empirical technical practice, which is applied only in the underground safety impact assessment stage, to the direction of controlling the inflow in the tunnel, is required. And the relationship between the groundwater level and the inflow of the tunnel required for setting the allowable inflow when planning the tunnel was derived. The introduction of a tunnel groundwater management concept is expected to help solve problems such as groundwater fluctuations, ground settlement, depletion of groundwater resources, and decline of maintenance performance in various urban deep tunnel construction projects to be promoted in the future.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.164-173
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• 2021

Recently, as underground space safety issues such as sink hole, ground subsidence and damage to old underground facilities have been increasing in urban areas, the precise management of underground facilities ins more required. Thus, this study developed a function to that, visualize on Integration Map of Underground Geospatial Information a real-time survey data of underground facilities acquired on site or underground facility survey data acquired through on-site survey after underground facility exploration and developed a function convert to surveying-results. In addition, using the on-site survey performance utilization function in connection with the Integration Map of Underground Geospatial Information developed through this study, the surveying -results obtained with the Total-station at the water pipeline burial construction site in Eunpyeong-gu, Seoul are visualized on the Integration Map of Underground Geospatial Information and On-site verification was performed by converting spatial-information performance files and transmitting the Integration Map of Underground Geospatial Information to the mobile center. Based on this, it was possible to verify the work procedure using the surveying-results in the area where the Integration Map of Underground Geospatial Information was built, and to review the direction of future improvement directions.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.3
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• pp.17-28
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• 2022

This study is to develop the direction of the development of the next-generation mapping of marine information required to develop a base of the utilization localization of maritime production tools. The GIS data-processing products and technologies currently used in the Korea's marine sector depend on external applications which is renewal costs, technical updates, and unreflected characteristics. Meanwhile, the S-100 standard, the next generation hydrographic data model that complements S-57's problems in marine GIS data processing, was adopted as a new marine data standard. This study aims to present the current status and problems of marine GIS technology in Korea and to suggest the development direction of GIS software based on the next generation hydrogrphic data model S-100 standard of IHO(International Hydrographic Organization). S-100-based marine GIS localization technology development and industrial ecosystem development research is expected to scientific decision-making on policy issues that occur with other countries such as marine territory management and development and use of marine resources.

• Journal of Korean Home Economics Education Association
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• v.34 no.2
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• pp.153-166
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• 2022

The purpose of this study is to develop and evaluate a dietary education program to improve the caring ability and multicultural acceptance of middle school students. Based on the instructional system design of ADDIE model, the dietary education program was developed to contain five sessions including four theoretical lectures and one lab session. Visual thinking technique was used to train students to express their thoughts and emotion by writing and drawing. The dietary education program was conducted for four weeks (from November 19 to December 14, 2018) at a middle school located in Seoul on a total of 69 middle school students, out of which 34 were assigned to an experimental group and 35 were assigned to a control group. Separate paired t-test were conducted for the experimental group and the control group, respectively, to determine the changes in caring ability and multicultural acceptance scores before and after the dietary education. There were significant increases in caring ability (dietary-, emotional-, behavioral- and cognitive caring) and multicultural acceptance (diversity, relationship and universality) scores among the experimental group after the dietary program. However, no differences were observed among the control group. The results indicate that the dietary education program can be an effective tool to improve caring ability and multicultural acceptance of middle school students.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.3
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• pp.201-220
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• 2023

Power cable tunnels is one of the underground structures meant for electricity transmission and are constructed using shield TBM method when transitting across urban and subsea regions. With the increasing shaft depth for tunnels excavation when the shield TBM excavated the rock mass, the review of selecting closed-type shield TBM in rocks becomes necessary. A simplified shield TBM design method is also necessary based on conventional geotechnical survey results. In this respect, design method and related design program are developed based on combined results of full-scale tests, considerable amount of accumulated TBM data, and numerical simulation results. In order to validate the program results, excavation data of a completed power cable tunnel project are utilized. Thrust force, torque, and power of shield TBM specification are validated using Kernel density concept which estimates the population data. The robustness of design expertise is established through this research which will help in stable provision of electricity supply.