• Journal of the Korea Society for Simulation
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• v.27 no.1
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• pp.91-99
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• 2018

Discrete event simulation environments often need to be modified because additional questions to systems may become apparent while observing the simulation results repeatedly. It leads to increasing development budget and depreciating the effectiveness of the environment. To avoid the modifications and to generate the altered results, this paper applies an Event Control Model (ECM) with control functions that modulate, delete and generate the events at the simulation time. In addition, this paper suggests an easier approach for domain-users, who do not want to program at source code level, by using ECM templates. The simulators with the ECMs can have better extensibility because it becomes more adaptable to possibly unanticipated changes. It prevents increasing development costs due to modifications or development of new models by M&S experts, and it provides a new alternative step to domain users. To support the effectiveness of this approach, this paper describes a relevant example, which is composed of an initial simulation model based on our empirical studies. It will show that there exist the uncountable benefits because the existing simulator is reused by domain users without new projects.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.2
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• pp.127-134
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• 2016

This paper presents practical issues for test and evaluation(T&E) methods to develop defense systems. Our argument is motivated by several domestic defense cases and the cases lead us to discuss two main factors for reliable defense systems development: 1) statistical approaches and 2) technical schemes. Specifically, statistical approaches enable to provide credible interpretations about T&E results in the decision-making process. With practical T&E results of the “Red Shark” torpedo, we performed statistical hypothesis tests and suggest a minimum sample size to accept the hypothesis. Next, technical schemes have more direct effects on improving reliability of developed defense systems and we shortly introduce tools development for systems verification that is required to integrate several sub-systems, e.g., combat, sensor, weapon, and communication systems, within a defense system. We additionally summary some domain cases using modeling and simulation techniques for successful T&E. In closing, we expect that the paper shows empirical investigation and lessons learned with these two practical issues, which provides a guide those who desire to make decisions about reliable defense systems development.

• Journal of Contemporary Eastern Asia
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• v.20 no.2
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• pp.40-62
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• 2021

Are intentions important in deciding the outcome of an action such as sharing misinformation among social media users during the pandemic? What is their role and how far they are important for the very act of fake sharing news? The social media users' actions on the social platform are determined by what they plan to do themselves; however, their motivation has an immense role to play in the dissemination of fake news on social media. The study proposes a conceptual model for understanding how select factors affect fake news sharing motivation and intentions of social media users. The study scrutinizes the relationship between content and context, fear of missing out (FoMO), news verification and news sharing gratification on the motivation and intention of social media users of networked Asian society. Empirical Data were drawn from social media users (N = 243) from India, using an online questionnaire based on prior studies and structural equation modeling (SEM) approach was used to analyze the data collected. Results indicate that news content, news verification, and news sharing gratification have a direct and positive relationship with sharing motivation. On the other hand, news context and content, FoMO and news sharing gratification have a positive significant relationship with sharing intention. Likewise, it was discovered that news verification will decrease sharing intention of the social media users. However, news context, that is the pandemic in the case of the present study and FoMO were not identified as determinant variables for sharing motivation among social media users. The research limitations and further scope were discussed.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.1-9
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• 2021

Although interest in the metaverse increases due to the pandemic, the understanding of the metaverse interest factor, which is an essential element for the sustainability of any metaverse platform, is lacking. This study aims to reveal the interest factors of metaverse services by analyzing user community discourse. We collected user community discourses from and applied LDA to extract topics. Further, we categorize the factors into growth and verifiable indicators, various levels of interaction, self-expression and freedom, and connection with the real world. The content planning direction of the game-based metaverse of utilization was derived. This study is meaningful in that it analyzes the interest factors of the metaverse based on the empirical evidence of user discourse data.

• Journal of the Korea Society of Computer and Information
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• v.26 no.5
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• pp.31-38
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• 2021

This study empirically investigated the user's experience with based on the Technology Acceptance Model. According to the frequency analysis results, the usability for learning was evaluated relatively higher than that for appreciation from the perspective of perceived usefulness and the technical factors such as graphics and modeling raised the issue for the quality improvement. According to the results of the correlation analysis, the usability for learning correlated with the degree of satisfaction. In addition, all detailed factors of perceived ease of use positively influenced on the degree of satisfaction and the impact of the environmental factor on the degree of satisfaction was greatest. The degree of satisfaction with the VR application significantly correlated with the degree of immersion and behavioral intention to the VR application. Therefore, this study proved the suitability for the Technology Acceptance Model as a tool for evaluating a VR application.

• International Area Studies Review
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• v.14 no.3
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• pp.131-154
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• 2010

This study tries to analyze what the most significant factors are in Brazil, where the Korean investing firms have to overcome and adapt to various difficulties, especially in terms of political environment. This main purpose of this research is to test empirically some relations of between the managing strategy of Korean firms and the environment factors of politics in Brazil while this is conducted in two stages. First, the research model is designed by reviewing relevant theories, previous studies, and the current investment conditions in local Brazil. Second, the survey of Korean firms engaged in investment activities in there is done by collecting questionnaires from them. with this survey, the strategic method of multiple regression is used to testing some hypotheses. At the result of Analysis, It is proved there haven been negative affecting political factors of law/regulation system and administrative operation service, and Korean firms have implementing the responding management strategies with reasonable adaptation to risks and human network reinforcement.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.137-149
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• 2019

Accurate estimation of reference evapotranspiration (RET) is important to quantify crop evapotranspiration for sustainable water resource management in hydrological, agricultural, and environmental fields. It is estimated by different methods from direct measurements with lysimeters, or by many empirical equations suggested by numerous modeling using local climatic variables. The potential to use some such equations depends on the availability of the necessary meteorological parameters for calculating the RET in specific climatic conditions. The objective of this study was to determine the proper RET equations using limited climatic data and to analyze the temporal and spatial trends of the RET in South Korea. We evaluated the FAO-56 Penman-Monteith equation (FAO-56 PM) by comparing several simple RET equations and observed small fan evaporation. In this study, the modified Penman equation, Hargreaves equation, and FAO Penman-Monteith equation with missing solar radiation (PM-Rs) data were tested to estimate the RET. Nine weather stations were considered with limited climatic data across South Korea from 1973 - 2017, and the RET equations were calculated for each weather station as well as the analysis of the mean error (ME), mean absolute error (MAE), and root mean square error (RMSE). The FAO-56 PM recommended by the Food Agriculture Organization (FAO) showed good performance even though missing solar radiation, relative humidity, and wind speed data and could still be adapted to the limited data conditions. As a result, the RET was increased, and the evapotranspiration rate was increased more in coastal areas than inland.

• Journal of the Korean Regional Science Association
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• v.35 no.1
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• pp.19-31
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• 2019

This study examines the effect of national identity and threat awareness on the multi-cultural acceptability and whether contact theory actually work. For the analysis, this study used '2013 Korea General Social Survey' data and compared two groups divided according to whether or not they live in ethnic places using structural equation modeling. The empirical analysis shows that national identity does not have a direct effect on multi-cultural acceptability, and threat awareness has a full mediating effect between national identity and multi-cultural acceptability. In addition, the negative effect of the threat awareness on multi-cultural acceptability was greater in groups living in ethnic places. The findings suggest that multi-cultural awareness education is necessary to reduce the threat awareness toward foreigners, and that community-level programs are needed to prevent and coordinate conflicts arising from contact between foreigners and Koreans.

• Journal of the Korean Geotechnical Society
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• v.36 no.12
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• pp.125-132
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• 2020

Embedded joints in the rock mass are a major constituent influencing its mechanical behavior. Numerical analysis requires a rigorous modeling methodology for the rock mass with detailed information regarding joint properties, orientation, spacing, and persistence. This paper provides a mechanical model for a jointed rock mass based on the implicit joint-continuum approach. Stiffness tensors for rock mass are evaluated for an assemblage of intact rock separated by sets of joint planes. It is a linear summation of compliance of each joint sets and intact rock in the serial stiffness system. In the application example, kinematic analysis for a planar failure of rock slope is comparable with empirical daylight envelope and its lateral limits. Since the developed implicit joint-continuity model is formulated on a continuum basis, it will be a major tool for the numerical simulations adopting published plenteous thermal-hydro-chemical experimental results.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.3
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• pp.23-34
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• 2018

Due to a waste of energy in korea, about 525,000 which are 75 percent of total buildings are at least 15 years old buildings that need remodeling. There are two current remodeling systems. One is a remodeling system to reduce a waste of resources from the reconstruction. The other is a green-remodeling system aimed to energy savings and reducing environmental costs. This study is to analyze quantitatively these current systems with respect to the cost-benefit caused by the life cycle and suggests the political and institutional implications through the interpretation of the results. For a quantitative analysis, we analyzed reducing maintenance costs and rent benefits with simulation by using opportunity costs, construction costs, plan costs and supervision costs as expense variables and using the reduced floor area ratio, institutional incentives, energy, water resources and certified emission reduction(CER) as benefit variables. As a result of the empirical study, the green-modeling was more beneficial in the field of environment such as the energy savings, however, the final benefits of remodeling which has no green building certification costs but more floor area ratio incentives were more economical. The green-remodeling system focused on reducing environmental costs and energy savings needs a equatable institutional incentive system.