• Journal of Korea Game Society
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• v.22 no.1
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• pp.87-98
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• 2022

With the development of fourth industrial revolution-related technology and increased demands for non-face-to-face services, VR games attract attention. This study collected VR game review data from an online game platform STEAM and analyzed chronical trends using text mining and word cloud analysis. According to the results, experience and perceived cost were major trends from 2016 to 2017, increased demands for FPS and rhythm games were from 2018 to 2019, and story and immersion were from 2020 to 2021. It aims to contribute to expanding the base of VR games by identifying the keywords VR users take interest in by period.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.11a
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• pp.169-172
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• 2001

There are many people who suffer from simulation sickness when immersing in virtual reality. In this study, we analyzed two photoplethysmogram(PPG) parameters - a second derivative parameter and power spectral density ratios - in order to relate PPG parameters with simulation sickness. 36 young, healthy subjects were participated in the experiment, and each subject was equipped with a PPG electrode during his or her immersion. Simulation sickness section was defined as a 7 - second section which starts from the point where a subject reported simulation sickness, and normal section as a same-length section where no physical stimuli was presented to him or her. We compared the PPG parameters of the simulation sickness sections with the normal sections, - d/a ratio is believed to have lower value during vasodilation and higher value during vasoconstriction, however, we could not find much difference in the parameter between normal and simulation sickness sections. We also compared 1 to 10Hz power spectral density ratios in normal sections with in simulation sickness section, and found that 6 density ratios among them have different value. Therefore, the density ratios might be utilized as parameters to detect simulation sickness of subjects.

• International Journal of Advanced Culture Technology
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• v.12 no.2
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• pp.110-118
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• 2024

This study was conducted to analyze the metaverse usage behavior of college students through in-depth interviews and to explore the characteristics of the major metaverse platforms with a focus on keywords. This study derived elements such as metaverse participation activities, real-world order, metaverse system, presence, and self-expression from previous research. This study examined how college students who use the metaverse perceive these variables. We present the following research results: First, the college students who participated in the study showed interest in content with many interactive elements on the metaverse platform and appeared to participate more actively in such content. Second, college students cited the ability to engage in economic activities in the metaverse as their greatest strength. It was expected that social norms applied in the real world would also be applied in the metaverse. Third, the Metaverse system, such as the Metaverse UI, UX, and servers, was found to be a factor that needs to meet users' expectations and hinders immersion. In this study, the characteristics of the metaverse platform were analyzed, focusing on essential keywords from in-depth interviews. The analysis results are as follows: It was expressed with keywords such as Zepeto has 'avatar' and 'personality expression,' Ifland has 'free decoration' and 'communication convenience,' Gathertown has 'movement convenience' and 'video chat.' Roblox has 'game-based' and 'dynamic.'

• International Journal of Advanced Culture Technology
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• v.12 no.1
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• pp.20-25
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• 2024

The qualitative effect of class is influenced by the instructor's class design and operation method, but it comes from motivating students to actively participate in class and utilizing potential qualities that lead to student-centered learning. Students' activities and the quality development of class participation can be utilized in presentation-based classes. This could be confirmed through the presentation classes in English language curriculum applied to English major students in Korea. In other words, with presentations conducted in language-theoretic classes such as phonetics/phonology, and syntax, it turned out that immersion in learning, concentration on class, and motivation for learning can be improved, developing systematic self-directed learning ability and cooperative mutual communication ability. Instructors need to lead the direction and design of the classes, but the actual educational effect depends on how students accept the academic tasks, how well they understand the learning contents, and how well they can systematically transmit them to others. In this respect, this study aims to investigate that learner-centered presentation classes contribute to making learners develop their competencies in class design, data utilization, imparting knowledge, and communication, which would bring about the improvement of learning quality and educational effects.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.158-163
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• 2024

Virtual world technology is driving major advances in education, entertainment, and professional training. Metaverse and extended reality (XR) technologies maximize immersion to enhance learning, provide global learning environments, and expose students to situations that are difficult to experience in real life. Career exploration is an important developmental task in adolescence, and virtual training maximizes learning by providing life-like experiences with imagery training. Virtual training overcomes spatial, financial, performance, and situational constraints and is effective in a variety of fields, including military and disaster training. It provides customized learning for various users such as youth, job seekers, and people with disabilities, deepening their understanding of professional activities and improving their problem-solving skills. It also improves the quality of learning through repetitive learning and contributes to the improvement of teamwork and communication skills, and helps to solve financial problems by using unlimited internal resources and space in virtual space, and enables people with disabilities to perform in various professions. This paper investigated the value of virtual training as a comprehensive educational tool through an economical and efficient learning experience.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.271-281
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• 2023

Background: This study aims to improve dental hygiene education by investigating the relationship between metacognition, learning flow, and problem-solving abilities in dental hygiene majors. Methods: A survey was conducted on 2nd to 4th-year students from dental hygiene programs, with 132 responses analyzed. Data analysis involved t-tests and ANOVA to examine the differences in metacognition, learning flow, and problem-solving abilities based on the general characteristics. Multiple regression analysis was employed to investigate the factors influencing the dependent variable, which is problem-solving abilities. The collected data were analyzed using SPSS. Results: First, when comparing metacognition, learning flow, and problem-solving abilities based on the general characteristics of the study participants, statistically significant differences were observed in common factors such as major satisfaction, subjective academic performance, GPA (grade point average), and reason for major choice (p<0.05). Second, it was found that there is a significant positive correlation between metacognition, learning flow, and problem-solving abilities in dental hygiene students (r≥0.79, p<0.05). In other words, higher levels of metacognition and learning flow were associated with better problem-solving abilities. Third, factors influencing problem-solving abilities were identified, with both metacognition and learning flow having a statistically significant positive impact. It was also noted that metacognition had a greater influence on problem-solving abilities compared to learning flow (adjusted R²=0.815, p<0.05). Conclusion: To enhance the core competency of problem-solving abilities, it is essential to improve metacognition and learning flow. To enhance metacognition and promote learning flow, strategies such as goal setting, utilizing effective learning methods, boosting self-efficacy, managing the learning environment, choosing activities that foster immersion, stress management, self-assessment and feedback integration, improving focus, and utilization a variety of learning experiences will be necessary.

• The Journal of Advanced Prosthodontics
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• v.1 no.2
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• pp.107-112
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• 2009

STATEMENT OF PROBLEM. Macroscopic and especially microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Dental implants with modified surfaces have shown stronger osseointegration than implants which are only turned (machined). Advanced surface modification techniques such as anodic oxidation and Ca-P application have been developed to achieve faster and stronger bonding between the host bone and the implant. PURPOSE. The purpose of this study was to investigate the effect of surface treatment of titanium dental implant on implant stability after insertion using the rabbit tibia model. MATERIAL AND METHODS. Three test groups were prepared: sandblasted, large-grit and acid-etched (SLA) implants, anodic oxidized implants, and anodized implants with Ca-P immersion. The turned implants served as control. Twenty rabbits received 80 implants in the tibia. Resonance frequencies were measured at the time of implant insertion, 2 weeks and 4 weeks of healing. Removal torque values (RTV) were measured 2 and 4 weeks after insertion. RESULTS. The implant stability quotient (ISQ) values of implants for resonance frequency analysis (RFA) increased significantly (P <. 05) during 2 weeks of healing period although there were no significant differences among the test and control groups (P >. 05). The test and control implants also showed significantly higher ISQ values during 4 weeks of healing period (P < .05). No significant differences, however, were found among all the groups. All the groups showed no significant differences in ISQ values between 2 and 4 weeks after implant insertion (P >. 05). The SLA, anodized and Ca-P immersed implants showed higher RTVs at 2 and 4 weeks of healing than the machined one (P < .05). However, there was no significant difference among the experimental groups. CONCLUSION. The surface-modified implants appear to provide superior implant stability to the turned one. Under the limitation of this study, however, we suggest that neither anodic oxidation nor Ca-P immersion techniques have any advantage over the conventional SLA technique with respect to implant stability.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.90-90
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• 2014

The Immersion Grating Infrared Spectrometer (IGRINS) is the first astronomical spectrograph that uses a silicon immersion grating as its dispersive element. IGRINS fully covers the H and K band atmospheric transmission windows in a single exposure. It is a compact high-resolution cross-dispersion spectrometer whose resolving power R is 40,000. An individual volume phase holographic grating serves as a secondary dispersing element for each of the H and K spectrograph arms. On the 2.7m Harlan J. Smith telescope at the McDonald Observatory, the slit size is $1^{{\prime}{\prime}}{\times}15^{{\prime}{\prime}}$. IGRINS has a plate scale of 0.27" pixel-1 on a $2048{\times}2048$ pixel Teledyne Scientific & Imaging HAWAII-2RG detector with a SIDECAR ASIC cryogenic controller. The instrument includes four subsystems; a calibration unit, an input relay optics module, a slit-viewing camera, and nearly identical H and K spectrograph modules. The use of a silicon immersion grating and a compact white pupil design allows the spectrograph collimated beam size to be 25mm, which permits the entire cryogenic system to be contained in a moderately sized ($0.96m{\times}0.6m{\times}0.38m$) rectangular Dewar. The fabrication and assembly of the optical and mechanical components were completed in 2013. From January to July of this year, we completed the system optical alignment and carried out commissioning observations on three runs to improve the efficiency of the instrument software and hardware. We describe the major design characteristics of the instrument including the system requirements and the technical strategy to meet them. We also present the instrumental performance test results derived from the commissioning runs at the McDonald Observatory.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1547-1553
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• 2011

An effective analytical method of gas chromatography/mass spectrometry (GC/MS) was developed for the rapid determination of essential oils in the crude extract of Acorus species (Acorus gramineus, Acorus tatarinowii, and Acorus calamus). Major phenypropanoids (${\beta}$,${\alpha}$-asarone isomers, euasarone, and methyleugenol) and ${\beta}$-caryophyllene in Acorus species were used as marker compounds and determined for the quality control of herbal medicines. To extract marker compounds, various extraction techniques such as solvent immersion, mechanical shaking, and sonication were compared, and the greatest efficiency was observed with sonication extraction using petroleum ether. The dynamic range of the GC/MS method depended on the specific analyte; acceptable quantification was obtained between 10 and 2000 ${\mu}g/mL$ for ${\beta}$-asarone, 10 and 500 ${\mu}g/mL$ for ${\alpha}$-asarone, 10 and 200 ${\mu}g/mL$ for methyleugenol, and between 5 and 100 ${\mu}g/mL$ for ${\beta}$-caryophyllene. The method was deemed satisfactory by inter- and intra-day validation and exhibited both high accuracy and precision, with a relative standard deviation < 10%. Overall limits of detection were approximately 0.34-0.83 ${\mu}g/mL$, with a standard deviation (${\sigma}$)-to-calibration slope (s) ratio (${\sigma}$/s) of 3. The limit of quantitation in our experiments was approximately 1.13-3.20 ${\mu}g/mL$ at a ${\sigma}$/s of 10. On the basement of method validation, 20 samples of Acorus species collected from markets in Korea were monitored for the quality control. In addition, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were performed on the analytical data of 20 different Acorus species samples in order to classify samples that were collected from different regions.

• Clean Technology
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• v.3 no.2
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• pp.36-46
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• 1997

CFC and organic chlorine solvents has been used in the fine machinery and electronics industries for a long time since they have various excellent properties as cleaning agents. However, it is inevitable that alternative cleaning agents should be used since CFC and organic chlorine solvents were identified as ozone-depleting chemicals. There are various alternative cleaning agents. Among them, aqueous/semi-aqueous cleaning agents are environmentally friendly and promising in the long term. And their use and developement are on the increase in advanced countries, but few in our countries. In this paper, the charactistics and major components aqueous/semi-aqueous cleaning agents are analyzed and compared. And various cleaning equipments for aqueous/semi-aqueous cleaning agents such as immersion cleaner, ultronsonic cleaners, power spray cleaner, and vibration or rotational cleaners are compared and evaluated. Finally, important consideration points for selction of a cleaning system are analyzed and suggested in this paper.