• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.207-207
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• 2022

Eating and cooking quality (ECQ) is one of the most complex quantitative traits in rice. The understanding of genetic regulation of transcript expression levels attributing to phenotypic variation in ECQ traits is limited. We integrated whole-genome resequencing, transcriptome, and phenotypic variation data from 84 Japonica accessions to build a transcriptome-wide association study (TWAS) based regulatory network. All ECQ traits showed a large phenotypic variation and significant phenotypic correlations among the traits. TWAS analysis identified a total of 285 transcripts significantly associated with six ECQ traits. Genome-wide mapping of ECQ-associated transcripts revealed 66,905 quantitative expression traits (eQTLs), including 21,747 local eQTLs, and 45,158 trans-eQTLs, regulating the expression of 43 genes. The starch synthesis-related genes (SSRGs), starch synthase IV-1 (SSIV-1), starch branching enzyme 1 (SBE1), granule-bound starch synthase 2 (GBSS2), and ADP-glucose pyrophosphorylase small subunit 2a (OsAGPS2a) were found to have eQTLs regulating the expression of ECQ associated transcripts. Further, in co-expression analysis, 130 genes produced at least one network with 22 master regulators. In addition, we developed CRISPR/Cas9-edited glbl mutant lines that confirmed the role of alpha-globulin (glbl) in starch synthesis to validate the co-expression analysis. This study provided novel insights into the genetic regulation of ECQ traits, and transcripts associated with these traits were discovered that could be used in further rice breeding.

• Knowledge Management Research
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• v.24 no.3
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• pp.195-215
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• 2023

In the telecommunications service industry, until now, it has been possible for Network Operators (NOs) to secure a competitive advantage to increase subscribers and profits through network investment. However, amid a big change to digital economy, network investment fails to lead to increase profits. These days platform companies without holing network infrastructure have a more competitive advantage and take more profits. This makes NOs gradually lose interest in network investment. The purpose of this paper is to find policy measures to promote network investment in digital economy. Specifically, we identify the factors influencing the network investment and promising policy measures energizing the investment, and then analyze their priorities and derive policy implications through Analytic Hierarchy Process (AHP) and Analytic Network Process (ANP). The results of this paper show that market competition is more preferred to public intervention in promoting network investment. However, in order to guarantee and expand the universal access to network, it is necessary to consider expanding the role of the public, focusing on non-economic areas.

• Korean Journal of Remote Sensing
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• v.39 no.6_3
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• pp.1721-1730
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• 2023

As awareness of the problem of global warming emerges around the world, the role of carbon sinks in settlement is increasingly emphasized to achieve carbon neutrality in urban areas. In order to manage carbon sinks in settlement, it is necessary to identify the current status of carbon sinks. Identifying the status of carbon sinks requires a lot of manpower and time and a corresponding budget. Therefore, in this study, a map predicting the location of trees was created using already established tree location information and Sentinel-2 satellite images targeting Seoul. To this end, after constructing a tree presence/absence dataset, structured data was generated using 16 types of vegetation indices information constructed from satellite images. After learning this by applying the Extreme Gradient Boosting (XGBoost) model, a tree prediction map was created. Afterward, the correlation between independent and dependent variables was investigated in model learning using the Shapely value of Shapley Additive exPlanations(SHAP). A comparative analysis was performed between maps produced for local parts of Seoul and sub-categorized land cover maps. In the case of the tree prediction model produced in this study, it was confirmed that even hard-to-detect street trees around the main street were predicted as trees.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.57-62
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• 2023

This research is a comparative analysis of the U.S. S&P 500 index using the volatility breakout strategy against the Buy and Hold approach. The volatility breakout strategy is a trading method that exploits price movements after periods of relative market stability or concentration. Specifically, it is observed that large price movements tend to occur more frequently after periods of low volatility. When a stock moves within a narrow price range for a while and then suddenly rises or falls, it is expected to continue moving in that direction. To capitalize on these movements, traders adopt the volatility breakout strategy. The 'k' value is used as a multiplier applied to a measure of recent market volatility. One method of measuring volatility is the Average True Range (ATR), which represents the difference between the highest and lowest prices of recent trading days. The 'k' value plays a crucial role for traders in setting their trade threshold. This study calculated the 'k' value at a general level and compared its returns with the Buy and Hold strategy, finding that algorithmic trading using the volatility breakout strategy achieved slightly higher returns. In the future, we plan to present simulation results for maximizing returns by determining the optimal 'k' value for automated trading of the S&P 500 index using artificial intelligence deep learning techniques.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.653-658
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• 2023

In systems like the combat management system of a naval ship or smart city of civilians, where many sensors and actuators are connected, the middle-ware DDS (Data Distribution Service) is mainly used to transmit large amounts of data. It is scalable and can effectively respond to the increase in sensors or equipment connected to the system in the future. The engineering control system (ECS), which plays an important role similar to the combat management system of a naval ship, still uses Server-Client model with industrial protocols such as Modbus and CAN (Controller Area Network) bus, to transmit data, which is unfavorable in terms of scalability. However, as automation and unmanned systems advance, more sensors and actuators are expected to be added, necessitating substantial program modification. DDS can effectively address such situations. The purpose of this study is to confirm the development possibility of an integrated monitoring and control system of a ship by using OpenDDS, which follows the OMG (Object Management Group) standard among the middle-ware DDS used in the combat management system. To achieve this goal, field equipment simulators and an ECS server were configured to perform field equipment data input/output and simulation using DDS was performed. The ECS prototype successfully handled data transmission, confirming that DDS is capable of serving as the middle-ware for the ECS of a ship.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.25-31
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• 2023

The dispute over the Northern Limit Line in the West Sea has been sharply opposed since the U.N. commander set it in August 1953 with the aim of preventing accidental armed conflict between the two Koreas in the waters of the Korean Peninsula. In 2022, for the first time since the division, North Korea made a missile provocation beyond the NLL. The purpose of this study is to identify how the research on the NLL, which is under way by North Korea's actual provocation, has been conducted and to suggest a direction to proceed. This study examined the trend of research using a total of five academic information DBs, including RISS and Scholar, focusing on academic papers studied on NLL from 1998 to 2023. As a result of examining the current status of each year, field, and research method, significant differences in research volume were identified according to the government's relationship with North Korea, and the research field had the most introduction of the concept of NLL and historical background, confirming the need to expand to more diverse fields to have international legal justification and justification for the NLL, considering the changing international environment according to the logic of power. In terms of final research methods, most of them were literature studies, so the need for quantitative research using interviews, surveys, and big data was also found. It is hoped that the analysis results of this paper will play a positive role in setting the research direction for the international response of the NLL in the future amid the interests of the international political environment that is still ongoing.

• Korean Journal of Materials Research
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• v.33 no.10
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• pp.406-413
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• 2023

This study used optical and scanning electron microscopy to analyze the surface oxidation phenomenon that accompanies a γ'-precipitate free zone in a directional solidified CM247LC high temperature creep specimen. Surface oxidation occurs on nickel-based superalloy gas turbine blades due to high temperature during use. Among the superalloy components, Al and Cr are greatly affected by diffusion and movement, and Al is a major component of the surface oxidation products. This out-diffusion of Al was accompanied by γ' (Ni₃Al) deficiency in the matrix, and formed a γ'-precipitate free zone at the boundary of the surface oxide layer. Among the components of CM247LC, Cr and Al related to surface oxidation consist of 8 % and 5.6 %, respectively. When Al, the main component of the γ' precipitation phase, diffused out to the surface, a high content of Cr was observed in these PFZs. This is because the PFZ is made of a high Cr γ phase. Surface oxidation of DS CM247LC was observed in high temperature creep specimens, and γ'-rafting occurred due to stress applied to the creep specimens. However, the stress states applied to the grip and gauge length of the creep specimen were different, and accordingly, different γ'-rafting patterns were observed. Such surface oxidation and PFZ and γ'-rafting are shown to affect CM247LC creep lifetime. Mapping the microstructure and composition of major components such as Al and Cr and their role in surface oxidation, revealed in this study, will be utilized in the development of alloys to improve creep life.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.100-115
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• 2023

The modernization of najeonchil, or mother-of-pearl lacquerware, began in the latter era of the Joseon period and started to set in during the phase of industrial development after the Korean War. Especially, the rise and fall of najeonchil during the first half of the 1900s fluctuated more compared to other types of craft. This paper focuses on the production, supply and demand activities of the works by Min Jong-tae, who was born in 1915, began his career in 1929 and devoted 70 years of his life creating najeonchil craft and furniture. As an apprentice under Jeon Sung-gyu, who revived the craft of najeonchil, Min Jong-tae was not only an artisan who ranked alongside Kim Bongryong, Song Juan, Shim Bugil, Kim Taehee, but also a businessman. In particular, Min led the boom of modern najeonchilgi during the 1970s-80s in Seoul, which was the most important market at that time. However, studies about Min Jong-tae are almost non-existence, despite his accomplishments. This study first describes how Min Jong-tae began the craft of najeonchil and early days of his career around the liberation period, then retraced his efforts in building a supply and demand system in the 1950s-60s. Moreover, this paper covers not only his creations of large-scale najeonchil furniture in the advent of an era of 'wardrobe culture' in the 1970s-80s, but also his exported pieces to Japan, including incense boxes and tea containers. In conclusion, this research derives the historical significance of Min Jong-tae's role as an artisan of najeonchil- designated as Seoul Intangible Cultural Heritage No. 14 in the field of craft.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.5
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• pp.265-278
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• 2022

R&D projects for product development are crucial for ventures' growth and success. Current study summarizes existing studies that identify the relationship between startup ventures' R&D department, R&D investment, and R&D cooperation on product development performance, and highlights the effects of business model as well as the roles of R&D activities for product development project that have been traditionally emphasized. In order to consider the effects of business models that were not previously available, the effects of these factors on product development performance were comprehensively analyzed. The research results with 180 venture cases surveyed on venture companies in the growth stage in Korea, showed that the effect of product development project activities measured by R&D department, R&D investment and R&D cooperation on product development performance is not evident. However, the effect of business model on product development time and product development performance measured by product innovation was confirmed. In particular, it was found that the clarity and uniqueness of the business model interacted with the R&D investment to shorten the product development time and directly increase the innovativeness of the developed product. Based on these analysis results, the implications of this study, limitations of the study, and the future research directions were described.

• Korean Journal of Radiology
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• v.21 no.4
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• pp.431-441
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• 2020

Objective: To compare the diagnostic performance and interobserver variability of strain ratio obtained from one or two regions of interest (ROI) on breast elastography. Materials and Methods: From April to May 2016, 140 breast masses in 140 patients who underwent conventional ultrasonography (US) with strain elastography followed by US-guided biopsy were evaluated. Three experienced breast radiologists reviewed recorded US and elastography images, measured strain ratios, and categorized them according to the American College of Radiology breast imaging reporting and data system lexicon. Strain ratio was obtained using the 1-ROI method (one ROI drawn on the target mass), and the 2-ROI method (one ROI in the target mass and another in reference fat tissue). The diagnostic performance of the three radiologists among datasets and optimal cut-off values for strain ratios were evaluated. Interobserver variability of strain ratio for each ROI method was assessed using intraclass correlation coefficient values, Bland-Altman plots, and coefficients of variation. Results: Compared to US alone, US combined with the strain ratio measured using either ROI method significantly improved specificity, positive predictive value, accuracy, and area under the receiver operating characteristic curve (AUC) (all p values < 0.05). Strain ratio obtained using the 1-ROI method showed higher interobserver agreement between the three radiologists without a significant difference in AUC for differentiating breast cancer when the optimal strain ratio cut-off value was used, compared with the 2-ROI method (AUC: 0.788 vs. 0.783, 0.693 vs. 0.715, and 0.691 vs. 0.686, respectively, all p values > 0.05). Conclusion: Strain ratios obtained using the 1-ROI method showed higher interobserver agreement without a significant difference in AUC, compared to those obtained using the 2-ROI method. Considering that the 1-ROI method can reduce performers' efforts, it could have an important role in improving the diagnostic performance of breast US by enabling consistent management of breast lesions.