• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3320-3325
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• 2023

The scaled water-cooled Reactor Cavity Cooling System (RCCS) experimental facility reproduces a passive safety feature to be implemented in Generation IV nuclear reactors. It keeps the reactor cavity and other internal structures in operational conditions by removing heat leakage from the reactor pressure vessel. The present work uses Flownex one-dimensional thermal-fluid code to model the facility and predict the experimental thermal-hydraulic behavior. Two representative steady-state cases defined by the bulk volumetric flow rate are simulated (Re = 2,409 and Re = 11,524). Results of the cavity outlet temperature, risers' temperature profile, and volumetric flow split in the cooling panel are also compared with the experimental data and RELAP system code simulations. The comparisons are in reasonable agreement with the previous studies, demonstrating the ability of Flownex to simulate the RCCS behavior. It is found that the low Re case of 2,409, temperature and flow split are evenly distributed across the risers. On the contrary, there's an asymmetry trend in both temperature and flow split distributions for the high Re case of 11,524.

• Journal of KIISE:Software and Applications
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• v.33 no.1
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• pp.44-57
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• 2006

With the rapid growth of network technology, two or more products from different vendors are integrated and interact with each other to perform a certain function in the latest systems. Thus. interoperability testing is considered as an essential aspect of correctness of integrated systems. Interoperability testing is to test the ability of software and hardware on different machines from different vendors to share data. Most of the researches model communication system behavior using EFSM(Extended Finite State Machines) and use EFSM as an input of test scenario generation algorithm. Actually, there are many studies on systematic and optimal test case generation algorithms using EFSM. But in these researches, the study for generating EFSM model which is a foundation of test scenario generation isn't sufficient. This study proposes an EFSM generating technique from informal requirement analysis document for more complete interoperability testing. and implements prototype of Test Case Generation Tool generating test cases semi-automatically. Also we describe theoretical base and algorithms applied to prototype implementation.

• Analyses & Alternatives
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• v.4 no.2
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• pp.103-132
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• 2020

The purpose of this study is to observe whether intergenerational differences exist in support among major Korean political parties and, if so, how they exist, based on the results of the survey conducted nationwide. To achieve the purpose of the study, a questionnaire was prepared based on conjoint analysis, and the collected data was analyzed by applying a random parameter logit model. The main results of model analysis are summarized as follows. First, among the policy variables, statistically significant results were observed in the generation of 20s and 30s for the education variable. It was found that both 20s and 30s aimed for equal education at a higher level than other generations. Especially, the highest intensity aim for equal education culture was observed in the 20s. Second, the coefficients of major political parties were observed with a high level of statistical significance. This appears to be a result suggesting that voters decide on their voting behavior through thorough policy comparisons in addition to comprehensive consideration on various current issues. Third, a clear support for conservative parties was observed in the generation of 20s. A clear and intense distribution of preference for political parties classified as conservatives was observed in the 20s generation, which can be said to be mainly college students. This seems to be a profound founding related to the issue of "conservatization of the 20s," which has recently become a hot topic in Korean society. Fourth, a high level of support for progressive parties was observed in the 30s and 40s. The Justice Party can be classified as a minority party in the National Assembly House as of January 2019. Nevertheless, it was maintained at a relatively high level in national recognition, and it is presumed that the background was high level of support from the 30s and 40s. Fifth, a large level of standard deviation was observed in the preference for conservative parties in the 50s. This means that some respondents who are in their 50s or older strongly support the Liberty Korea Party, and some respondents in the same generation strongly disapprove it. Due to this countervailing power, it seems that the average support level for the Liberal Korean Party is low in the generations of 50s and older.?

• Journal of the Korean Society for Precision Engineering
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• v.26 no.11
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• pp.138-145
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• 2009

A suspended membrane micro fluidic heat flux sensor that is able to measure the heat flow rate was designed and fabricated by a complementary-metal-oxide-semiconductor-compatible process. The combination of a thirty-junction gold and nickel thermoelectric sensor with an ultralow noise preamplifier, low pass filter, and lock-in amp has enabled the resolution of 50 nW power and provides the sensitivity of $11.4\;mV/{\mu}W$. The heater modulation method was used to eliminate low frequency noises from sensor output. It is measured with various heat flux fluid of DI-water to test as micro fluidic application. In order to estimate the heat generation of samples from the output measurement of a micro fluidic heat-flux sensor, a methodology for modeling and simulating electro-thermal behavior in the micro fluidic heat-flux sensor with integrated electronic circuit is presented and validated. The electro-thermal model was constructed by using system dynamics, particularly the bond graph. The electro-thermal system model in which the thermal and the electrical domain are coupled expresses the heat generation of samples converts thermal input to electrical output. The proposed electro-thermal system model shows good agreement with measured output voltage response in transient state and steady-state.

• Journal of Radiation Protection and Research
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• v.42 no.1
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• pp.56-62
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• 2017

Background: To help future generations make accurate value judgments about nuclear power generation and radiation, this study will provide an effective education plan suitable for South Korea by applying and analyzing programs for the understanding of nuclear power within the diversely operated programs in the current Korean education system. Materials and Methods: This study analyzed the difference in educational effects by operating a 13-session regular curriculum for one semester and a one-session short-term curriculum from March to July 2016. Results and Discussion: As a result of operating a 13-session model school and a one-time educational program to analyze behavior changes against the traditional learning model, it was found that all elementary, middle and high school students showed higher acceptability of nuclear power in South Korea. The variation was greater for the model school than the short-term program. Conclusion: To prevent future generations from making biased policy decisions stemming from fear regarding nuclear power, it is necessary to bolster their value judgments in policy decisions by acquiring sufficient information about nuclear power generation and radiation through educational programs.

• Asia pacific journal of information systems
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• v.14 no.2
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• pp.37-59
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• 2004

Team decision making is a collective behavior that needs to be understood by considering properties belonging to team and individual member domains together. This paper introduces a conceptual model called "Dual-Level(DL)" model that describes a team decision-making process in terms of team level, member level, and the relationship between them. The team-level view explains the decision-making process by considering the team as a wholeand divides the process into three stages: Problem Conceptualization, Alternative Generation, and Selection. The member-level view describes what happens to individual members when they go through the group process and splits it into the five phases: Individual Cognitive Mapping, Problem Decomposition, Subproblem Session, Subproblem Integration, and Team Decision. The DL model works as a theoretical framework to explore team decision making by using a set of computational models of team design and team members. In practice, the conceptual framework is used to build a computational model of decision making team, called "Team-Soar."

• Journal of Distribution Science
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• v.21 no.11
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• pp.103-111
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• 2023

Purpose: This research aims to study the selection attributes influencing the purchasing decisions of the MZ generation in online luxury stores and explores the moderating effects of consumer value. The research aims to validate the impact of reasonable pricing, brand reliability, product variety, comprehensive product information, and user-friendly interfaces on customers' decision to purchase products from online luxury stores. Research design, data and methodology: A survey was conducted with 101 participants, and data analysis included exploratory and confirmatory factor analysis, as well as covariance structure model analysis. Results: The findings reveal that brand trust, product variety, and information sufficiency significantly influence brand affect, which in turn influences purchase intention. Additionally, the study identifies that consumers prioritizing hedonic value are more influenced by brand trust and information, while those prioritizing utilitarian value are more responsive to factors like reasonable price, product variety, and ease of use. Conclusions: The study provides insights into the preferences and behaviors of the MZ generation, highlighting their digital proficiency, mobile-centric lifestyle, desire for product variety, price-consciousness, social media influence, and the availability of personalized shopping experiences as factors contributing to their preference for online luxury stores. These findings contribute to understanding consumer behavior and decision-making processes in the context of online luxury shopping.

• Journal of the Korean Society for Railway
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• v.14 no.5
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• pp.398-403
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• 2011

When a crack exists under a residual stress, for example in welds, the crack can be closed and it shows non symmetric behavior for tension and compression. Ultrasonic detection method for those nonlinear cracks has been developed recently. The method uses the higher order harmonics generating at the crack surface. In this study, parameter study was carried out for the analysis of the harmonics generation at a nonlinear contact interface as a preliminary study for general 3-dimensional cracks. One-dimensional problem with simple bilinear behavior for the contacting surface was considered. The amplitude of second harmonic to the fundamental wave was obtained for various stiffness ratios, incident frequencies, and the contacting layer thicknesses.

• Journal of Korea Game Society
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• v.8 no.1
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• pp.79-90
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• 2008

This paper describes a motivation-based hierarchical behavior planning framework to allow autonomous agents to select adaptive actions in simulation game environments. The combined behavior planning system is formed by four levels of specification, which are motivation extraction, goal list generation, action list determination and optimization. Our model increases the complexity of virtual human behavior planning by adding motivation with sudden and cumulative attributes. The motivation selection by probability distribution allows NPC to make multiple decisions in certain situations in order to embody realistic virtual humans. Hierarchical goal tree enhances the effective reactivity. Optimizing for potential actions provides NPC with safe and satisfying actions to adapt to the virtual environment. A restaurant simulation game was used to elucidate the mechanism of the framework.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1995.10a
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• pp.60-63
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• 1995

The behavior of the work materials in the chip-tool interface in extremely high strain rates and temperatures is more that of viscous liquids than that of normal solid metals. In these circumstances the principles of fluid mechanics can be invoked to describe the metal flow in the neighborhood of the cutting edge. In the present paper an Eulerian finite element model is presented that simulates metal flow in the vicinity of the cutting edge when machining a low carbon steel with carbide cutting tool. The work material is assumed to obey visco-plastic (Bingham solid) constitutive law and Von Mises criterion. Heat generation is included in the model, assuming adiabatic conditions within each element. the mechanical and thermal properties of the work material are accepted to vary with the temperature. The model is based on the virtual work-stream function formulation, emphasis is given on analyzing the formation of the stagnant metal zone ahead of the cutting edge. The model predicts flow field characteristics such as material velocity effective stress and strain-rate distributions as well as built-up layer configuration