• Journal of KIISE:Software and Applications
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• v.29 no.6
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• pp.377-385
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• 2002

An authentic simulation platform for events situated in spatio-temporal space is presented. The authenticity, i.e., logical fidelity to the reality, of this cyberspace is realized by maximizing the diversity and unpredictability of events occurring therein. The knowledge components and associated schemes required for the simulation of events situated in spatio-temporal space encompass the environmental factors, the objects, the events, and their interrelations. We deviled event activation, triggering mechanism, and cognitive function related to event to realize an authentic simulation of discretionary events. The agents in this simulation environments are autonomous in that they have their own existence and capability of event planning. We focused on identifying basic constructs relevant to authentic simulation of discretionary events whose initiation depends on human intention. Several key ideas are implemented in a typical spatio-temporal situation to demonstrate the viability of our simulation mechanism.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.6
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• pp.1042-1062
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• 2010

Cooperative spectrum sensing (CSS) is an effective technology for alleviating the unreliability of local spectrum sensing due to fading/shadowing effects. Unlike most existing solutions, this paper considers the use of CSS technology in decentralized networks where a fusion center is not available. In such a decentralized network, some attackers may sneak into the ranks of cooperative users. On the basis of recent advances in bio-inspired consensus algorithms, an attack-proof, decentralized CSS scheme is proposed in which all secondary users can maintain cooperative sensing by exchanging information locally instead of requiring centralized control or data fusion. Users no longer need any prior knowledge of the network. To counter three potential categories of spectrum sensing data falsification (SSDF) attacks, some anti-attack strategies are applied to the iterative process of information exchange. This enables most authentic users to exclude potentially malicious users from their neighborhood. As represented by simulation results, the proposed scheme can generally ensure that most authentic users reach a consensus within the given number of iterations, and it also demonstrates much better robustness against different SSDF attacks than several existing schemes.

• Educational Technology International
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• v.25 no.1
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• pp.93-127
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• 2024

This study evaluates the effect of structured debriefing for a business simulation game for university students. The program provides an authentic learning experience of real-world business management by allowing learners to make decisions related to R&D, marketing, production, and finance through a business simulation game, and check the results in real time. In 2022, University A and B each ran a business simulation game-based program as an extra-curricular activity. University A conducted a traditional instructor-led debriefing where the instructor explained the summarized process and results, while University B implemented a structured debriefing which had been developed based on Gibbs' and 3D models. To assess the effect of the structured debriefing compared to the traditional instructor-led debriefing, business knowledge and entrepreneurship competencies were measured three times. Repeated measures ANOVA was used to test for the differences between the two groups and to examine interaction effects between group and time. The structured debriefing group achieved statistically significantly higher academic scores than the traditional instructor-led debriefing group at the post-test and in 2 weeks. There was no statistically significant difference between the groups in terms of entrepreneurship competencies. There was no interaction effect between group and time, both in academic achievement and in entrepreneurship competencies. In conclusion, the simulation game-based program integrated with the structured debriefing session is more likely to have a stronger impact on academic achievement and its retention.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.47-54
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• 2017

This study examines the implementation of a kinematic machining tool to evaluate the interference and collision phenomenon of 5-axis machining of wing ribs from airplanes, particularly for a large-size model airplane. We develop a machine simulation model of a parallel kinematic machining tool that can operate in a virtual space, which is equivalent to the authentic conditions in the field. The investigation of the simulation function elements indicates the necessity to generate the 6-axis machining, which attaches an angle head to the main axis of the machine. Using an NC program for the wing ribs, we attempt to verify the correspondence and conformity between the machine simulation model and the actual equipment.

• The KIPS Transactions:PartB
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• v.10B no.7
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• pp.785-794
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• 2003

Computer simulation of natural phenomena has been inclined to graphic processing for visual reality. This negligence of cosmic causalities in their occurrence and natural laws in their development should lead to limited degree of immersion to the users. We attempt to develop a logical framework for authentic simulation of diverse, unpredictable occurrence and development of natural phenomena (such as solar radiation and wind) based on their associated inherent laws and principles. To this end we structure the relevant objects organized in an ontology and propose a data management method. Then we describe our simulation method for the natural phenomena as delimited in phases and present modeling techniques for qualitative changes of physical objects due to their factors' values beyond normal ranges.

• Journal of KIBIM
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• v.6 no.3
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• pp.34-41
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• 2016

The previous studies argue that using the semantic properties of BIM objects is efficient for simulating the behaviors of autonomous, computer agents, called virtual-users, but such assumption is not proven via evidence-based research approaches. Hence, this present study aims to investigate the empirical effects of a human behavior simulation model equipped the semantics of spaces on the architecture-major students' operation and understanding of the simulation system, compared to a typical path-finding model. To achieve the aim, this study analyzed the survey and interview data, collected in the authentic design projects. The analysis indicates that (1) using a simulation model equipped the semantics of spaces helps the students' operation of the simulation, and (2) it also aids understanding the relationship between the variables of spaces and virtual-users (${\alpha}=0.74$). In addition, the qualitative data inform that the advantages of the simulation model that computes the semantics of spaces stem in the automatic behavioral changes of massive numbers of virtual-users, and efficient detection and activation on the what-if situations. The analysis also reveals that the simulation model has shortcomings in orchestrating the complex data structure between the semantics properties of spaces and virtual-users under multi-sequential scenarios. The results of this study contribute to develop a future design system combining BIM with human behavior simulation.

• The Mathematical Education
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• v.59 no.3
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• pp.271-294
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• 2020

The purpose of this study was to explore the possibility of digital simulation by which pre-service teachers (PSTs) can approximate the core teaching practice of eliciting student thinking. This study examined PSTs' questions to elicit student thinking, their use of "pause" session and peer feedback, and their reflections on doing a digital simulation. We analyzed a two-hour digital simulation session with 13 PSTs who enrolled in the elementary mathematics methods course. The results showed that PSTs shifted their general questions to more content-specific questions throughout the simulation and made a quick transition to comparing students' strategies. The number of lead PST-initiated "pause" ranged one to four times for various reasons. Their peer-coaches did not voluntarily "pause" the simulation session but actively shared what they noticed from the student work samples and suggested the next teaching moves. Without utilizing the pause session, the dramatic improvement of questioning was not observed. Even though the PSTs felt overwhelmed with interacting with the student-avatars in real-time, they highlighted the benefits of simulations, appreciated the opportunity to learn the core teaching practice, and viewed this digital simulation as "real" and "authentic" experience. The findings of this study provide implications for re-designing a practice-based teacher education program.

• Journal of the Korean Society of Safety
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• v.30 no.2
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• pp.56-62
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• 2015

The purpose of this study was to identify the relationship between the index of Electrocardiography(LF/HF) and the occurrence of drowsiness driving while driving in a simulated situation. Participants were 31 undergraduate students with an experience in driving and they participated 30 minutes driving under enough sleep condition and 1 hour under the sleep deprivation condition. The Euro Truck Simulator II was used for driving simulation task and ECG and perceived drowsiness of each participants were measured during two driving conditions. Perceived sleepiness recorded by the checklist every 10 minutes and ECG data extracted before and after 15 seconds of every 10 minutes to verify the relationship between two variables. The results showed that the level of perceived sleepiness under sleep deprivation condition was higher than that under the enough sleep condition, and the level of LF/HF under sleep deprivation condition was lower than that under the enough sleep condition. In addition, the result of analysis of repeated measure ANOVA for ECG indicated that authentic sleepiness revealed in 20 minutes after the start of driving under the sleep deprivation condition. However, the result of perceived drowsiness indicated that authentic sleepiness revealed in 30 minutes after the start of driving. These result suggest that the time difference between biological and perceived response on drowsiness may be exist. Finally, the significant negative correlation between the LF/HF level and perceived drowsiness was observed. These findings suggest that ECG(LF/HF) can be an possible index to measure drowsiness driving.

• Journal of KIBIM
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• v.10 no.4
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• pp.1-10
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• 2020

While the importance of barrier-free and fire evacuation design is highlighted in architectural design education, systemic analysis, and examination on such performances are still challenging due to methodological lacks. The present study investigates the effectiveness of BIM-based human behavior simulation for architecture major students' analytical examinations to promote barrier-free and fire evacuation performances. To achieve such an aim, quasi-experiments were conducted, which compare 50 students' analysis and examination scores according to the use and non-use of the simulation, and the data were collected via participants' survey and interview. As a result, T-Test and MANOVA analyses indicate that, compared with its non-use counterpart, the use of human behavior simulation better facilitates the students' (1) examination of the physical properties and dimensions for the disabled's accessibility and evacuation, (2) understanding of the bodily capacity and handicap of the disabled, (3) examination on the spatial layouts and locations of exits, (4) understanding on evacuees' urgent behaviors, and (5) responsibility as an architect. Based on previous studies, the reasons of statistical results are interpreted as the explicit observation and analytical measures of multiple numbers of virtual-evacuees and direct-experience from body range of the disabled responding to the populated occupants as what they face in authentic reality.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.147-149
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• 2004

There are no authentic solutions in a face region extraction problem though it is an important part of pattern recognition and has diverse application fields. It is not easy to develop the facial region extraction algorithm because the facial image is very sensitive according to age, sex, and illumination. In this paper, to solve these difficulties, a fuzzy color filer based on the facial region extraction algorithm is proposed. The fuzzy color filter makes the robust facial region extraction enable by modeling the skin color. Especially, it is robust in facial region extraction with various illuminations. In addition, to identify the fuzzy color filter, a linear matrix inequality(LMI) optimization method is used. Finally, the simulation result is given to confirm the superiority of the proposed algorithm.