• Journal of the Korean Society of Systems Engineering
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• v.18 no.2
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• pp.108-116
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• 2022

Accurately predicting wartime resources requirements and preparing war supplies in peacetime is an important task that can determine the outcome of the war by guaranteeing the duration of the operation. The wartime warship damage rate is a measure of estimating the battle damage of our warships in the process of performing battles to achieve the war goal. In the previously studied wartime warship damage rate estimation method, when damage occurs, long-term repair is required due to the complexity and specificity of the ship structure. Only the case of a complete defeat at the level of sinking was defined as a damage, and even if it was impossible to perform a maritime operation mission, it was not estimated as a damage if the level of sinking was not reached. Therefore, in order to improve the reliability of the wartime warship damage rate, the equipment damage assessment level can be estimated based on the warhead weight of the threat weapon system, the vulnerability rate of the warship's equipment, and the warship's hull. In the future, it is expected that the estimation methodology proposed in this study will be used as a simulation logic when developing a model for analyzing the wartime resources requirements for the warship's equipment and hull.

• Journal of Korea Foundry Society
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• v.43 no.4
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• pp.194-200
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• 2023

The heat transfer of the mold in the casting process has been calculated by considering the mold as a uniform isotropic material. Since the mold was not a uniform isotropic material, however, the calculation was performed with approximate values, and in particular, estimated values were used when considering compaction and the amount of added binder. In this study, a calculation algorithm of the thermal properties of the sand mold was developed. An algorithm for calculating the thermal conductivity and specific heat based on a thermal resistance model in the case of mono-dispersed sand grains was also developed and applied to sand molds with various size distributions. The thermal properties of sand were calculated for artificial sand, and relatively close values compared to the experimental values were obtained.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2D
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• pp.181-190
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• 2010

The purpose of this study is to propose an effective approach of making route decisions for the large-scale national project (i.e. the KTX Gyeongbu line between Daegu and Busan) by analyzing the conflicts that had occurred in the process of selecting the routes and stations. This study investigated policy making processes and conflicts during the construction of the KTX Gyeongbu line. The five contentious issues were 1) selecting the route between Daegu~Busan line, 2) developing a new route through Gyeongju areas, 3) making decisions of the first and second phases of construction, 4) setting up an extra station in Ulsan, and 5) conflicts of the Mt. Cheonseong route in Yangsan. In terms of analyzing these issues, the current study focuses on dealing with notions of technical, economical, legal, social, and practical rationality. Based on such analyses and implications, this study proposes a relatively reasonable model of line decision making especially for long-distance intercity routes. It also turns out that the large-scale project like the development of KTX Gyeongbu line should be conducted after receiving enough quantitative evaluation by reviewing relevant technical research studies and economic analyses, and having social agreements to prevent plausible conflicts.

• Computers and Concrete
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• v.32 no.1
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• pp.61-74
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• 2023

This article investigates the wave propagation analysis of the imperfect functionally graded (FG) sandwich plates based on a novel simple four-variable integral quasi-3D higher-order shear deformation theory (HSDT). The thickness stretching effect is considered in the transverse displacement component. The presented formulation ensures a parabolic variation of the transverse shear stresses with zero-stresses at the top and the bottom surfaces without requiring any shear correction factors. The studied sandwich plates can be used in several sectors as areas of aircraft, construction, naval/marine, aerospace and wind energy systems, the sandwich structure is composed from three layers (two FG face sheets and isotropic core). The material properties in the FG faces sheet are computed according to a modified power law function with considering the porosity which may appear during the manufacturing process in the form of micro-voids in the layer body. The Hamilton principle is utilized to determine the four governing differential equations for wave propagation in FG plates which is reduced in terms of computation time and cost compared to the other conventional quasi-3D models. An eigenvalue equation is formulated for the analytical solution using a generalized displacements' solution form for wave propagation. The effects of porosity, temperature, moisture concentration, core thickness, and the material exponent on the plates' dispersion relations are examined by considering the thickness stretching influence.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.01a
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• pp.439-441
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• 2023

National park is one of the important types of protected area management systems established by IUCN and a management model for effective conservation and sustainable use of natural and cultural heritage in countries around the world, and it assumes important roles in conservation, scientific research, education, recreation and driving community development. This study takes Liaohe National Park in China, a typical representative of global coastal wetlands, as a case study, and uses python technology to collect travelogues and reviews of visitors from Mafengwo.com, Ctrip.com, Go.com, Meituan.com and Dianping.com as a source, and the text spans from 2015 to 2022. The results show that wildlife resources, natural landscape with river and sea, wetland ecology and fishing and hunting culture of northern China are fully reflected in the perceptions of visitors to Liaohe National Park. However, there is still much room for improvement in terms of supporting services and facilities, public education and tourists' experience and participation in Liaohe National Park. In this paper, we use python data visualization technology to study the public perception of wetland wildlife as the theme, and grasp the satisfaction, spatial distribution, activity content and emotional tendency of the public in the process of wetland wildlife as the theme, so as to better promote the Liaohe National Park to better carry out the public experience while strictly adhering to ecological protection, and to provide the Liaohe National Park with a better opportunity to This will provide scientific basis for the Liaohe National Park to play a better role in ecological civilization construction and education of ecological civilization awareness.

• Korea Trade Review
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• v.47 no.3
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• pp.57-73
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• 2022

The process and change of convergence in the economy and industry with the development of digital technology and combining with new technologies is called Digital Transformation. Specifically, it refers to innovating existing businesses and services by utilizing information and communication technologies such as big data analysis, Internet of Things, cloud computing, and artificial intelligence. Digital transformation is changing the shape of business and has a wide impact on businesses and consumers in all industries. Among them, the big data and analytics market is emerging as one of the most important growth drivers of digital transformation. Integrating intelligent data into an existing business is one of the key tasks of digital transformation, and it is important to collect and monitor data and learn from the collected data in order to efficiently operate a data-based business. In developed countries overseas, research on new business models using various data accumulated at the level of government and private companies is being actively conducted. However, although the trade and import/export data collected in the domestic public sector is being accumulated in various types and ranges, the establishment of an analysis and utilization model is still in its infancy. Currently, we are living in an era of massive amounts of big data. We intend to discuss the value of trade big data possessed from the past to the present, and suggest a strategy to activate trade big data for trade digital transformation and a new direction for future trade big data research.

• Knowledge Management Research
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• v.24 no.3
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• pp.127-148
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• 2023

Traditional Business Intelligence environment is limited to support the rapidly changing businesses and the exponential growth of data in both volume and complexity of data. Companies should shift their business intelligence environment into Self-Service Business Intelligence (SSBI) environment in order to make smarter and faster decisions. However, firms seem to face various challenges in implementing and leveraging the effective business intelligence system, and academics do not provide sufficient studies related including the success factors of SSBI. This study analyzes the three cases of Korean companies in depth, their development process and the assessment of business intelligence, based on the theoretical model on the key success factors of business intelligence systems. The comparative analysis of the three cases including project managers' interviews and performance evaluations provide rich implications for the successful adoption and the use of business intelligence systems of firms. The study is expected to provide useful references for firms to fully leverage the effects of business intelligence systems and upgrade towards self-service business intelligence systems.

• Journal of Biomedical Engineering Research
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• v.45 no.2
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• pp.90-94
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• 2024

Diagnosing wounds presents a significant challenge in clinical settings due to its complexity and the subjective assessments by clinicians. Wound deep learning algorithms quantitatively assess wounds, overcoming these challenges. However, a limitation in existing research is reliance on specific datasets. To address this limitation, we created a comprehensive dataset by combining open dataset with self-produced dataset to enhance clinical applicability. In the annotation process, machine learning based on Gradient Vector Flow (GVF) was utilized to improve objectivity and efficiency over time. Furthermore, the deep learning model was equipped U-net with residual blocks. Significant improvements were observed using the input dataset with images cropped to contain only the wound region of interest (ROI), as opposed to original sized dataset. As a result, the Dice score remarkably increased from 0.80 using the original dataset to 0.89 using the wound ROI crop dataset. This study highlights the need for diverse research using comprehensive datasets. In future study, we aim to further enhance and diversify our dataset to encompass different environments and ethnicities.

• International Journal of Advanced Culture Technology
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• v.12 no.2
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• pp.236-248
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• 2024

This study aims to empirically analyze the effects of leadership level and toxic leadership on leadership performance results among male and female military leaders in the Army, and to verify whether the leader's gender has a moderating effect in this process. Additionally, by comparing and analyzing the leadership level, toxic leadership, and leadership performance results of female military leaders by position, this study seeks to examine the characteristics of female military leadership according to position. The research model was established with leadership level and toxic leadership as independent variables, leadership performance results as the dependent variable, and the leader's gender as a moderating variable. Data were collected through a survey of 216 male and female officers serving in the positions of platoon leader, company commander, and battalion commander in the Army. The collected data were analyzed using descriptive statistics, reliability analysis, correlation analysis, and hierarchical regression analysis. The results showed that leadership level had a significant positive effect on leadership performance results, while toxic leadership had a significant negative effect. The leader's gender moderated the relationship between leadership level and leadership performance results, with female leaders receiving lower evaluations than male leaders at the same level of leadership competency. Gender also moderated the relationship between toxic leadership and leadership performance results, with female leaders exhibiting the same level of toxic leadership receiving lower performance evaluations than male leaders. In the comparative analysis of female military leadership characteristics by position, the leadership level of the platoon leader and company commander groups was not significantly different from that of male soldiers, but the battalion commander group showed slightly lower leadership competency compared to male soldiers. Based on these results, this study suggests ways to improve the leadership level of female military leaders, reduce toxic leadership, and prepare support measures to strengthen the leadership competency of female military officers at the battalion commander level and above from policy, institutional, and educational perspectives.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.125-137
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• 2024

Background: The Korea Risk Information Surveillance System (K-RISS) was developed to enable the early detection of food and drug safety-related issues. Its goal is to deliver real-time risk indicators generated from ongoing food and drug risk monitoring. However, the existing K-RISS system suffers under several limitations. Objectives: This study aims to augment K-RISS with more detailed indicators and establish a severity standard that takes into account structural changes in the daily time series of K-RISS values. Methods: First, a Delphi survey was conducted to derive the required weights. Second, a control chart, commonly used in statistical process controls, was utilized to detect outliers and establish caution, attention, and serious levels for K-RISS values. Furthermore, Bai and Perron's method was employed to determine structural changes in K-RISS time series. Results: The study incorporated 'closeness to life' and 'sustainability' indicators into K-RISS. It obtained the necessary weights through a survey of experts for integrating variables, combining indicators by data source, and aggregating sub K-RISS values. We defined caution, attention, and serious levels for both average and maximum values of daily K-RISS. Furthermore, when structural changes were detected, leading to significant variations in daily K-RISS values according to different periods, the study systematically verified these changes and derived respective severity levels for each period. Conclusions: This study enhances the existing K-RISS system and introduces more advanced indicators. K-RISS is now more comprehensively equipped to serve as a risk warning index. The study has paved the way for an objective determination of whether the food safety risk index surpasses predefined thresholds through the application of severity levels.