• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.266-271
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• 2011

Single-walled carbon nanotube (SWCNT)/Epoxy composites were prepared for improving thermal conductivities and dispersion of SWCNTs in the epoxy matrix. Composites obtained different types of SWCNTs which are pristine and functionalized of the SWCNTs by acid and amine treatments. Three types of SWCNTs were dispersed in diglycidyl ether of bisphenol A (DGEBA) and bisphenol F (DGEBF). Enhanced interaction between functional groups on SWCNT and epoxy resins was evidenced by an improvement in the dispersion of the SWCNTs in the epoxy matrix. Thermal conductivity of composites containing acid SWCNTs were found to be much better than those containing pristine and amine treated SWCNTs.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.213-223
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• 2021

In this study, a smartphone utilization system was designed to explore ways to use smartphones owned by more than 95% of Korean teenagers in school classes. First, the necessary functions were selected based on the factors related to adolescents and the factors of distraction, dependence, motivation, and cooperation in the preceding studies on the use of smartphone classes, and then three versions of the application were composed according to the educational roles of students, teachers, and parents. By using these applications, students can learn self-study, motivate learning, and actively interact, teachers can be more closely with students and facilitate lessons while giving detailed feedback, and parents can check the student's safe learning using smartphones. It is hoped that this measure will help to increase the educational effect by activating the use of smartphones in school classes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.386-392
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• 2021

Multiferroics exhibiting the coexistence and a possible coupling of ferromagnetic and ferroelectric order are attracting widespread interest in terms of academic interests and possible applications. However, room-temperature single-phase multiferroics with soft ferromagnetic and displacive ferroelectric properties are still rare owing to the contradiction in the origin of ferromagnetism and ferroelectricity. In this study, we demonstrated that sizable ferromagnetic properties are induced in the ferroelectric bismuth ferrite-barium titanate system simply by introducing Co ions into the A-site. It is noted that all modified compositions exhibit well-saturated magnetic hysteresis loops at room temperature. Especially, 70Bi_0.95Co_0.05FeO₃-30Ba_0.95Co_0.05TiO₃ manifests noticeable ferroelectric and ferromagnetic properties; the spontaneous polarization and the saturation magnetization are 42 µC/cm² and 3.6 emu/g, respectively. We expect that our methodology will be widely used in the development of perovskite-structured multiferroic oxides.

• Knowledge Management Research
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• v.22 no.4
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• pp.41-70
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• 2021

The use of social media has many advantages such as knowledge sharing, social networking, and communicating with other people. However, it has given rise to various side effects including stress, Which is defined as social network stress in this study. This study aims to conceptualize social network stress and investigate its effect on switching behavior in social media. For this purpose, we present a research model that consists of the antecedents and consequences of social network stress and test it empirically using LISREL 8.7 based on the structural equation model. The empirical results showed that knowledge sharing and self-disclosure had positive impact on social network stress, which in turn positively influenced social media switching behaviors. In conclusion, we discussed both theoretical and practical implications of this research and suggested its limitations.

• Journal of Broadcast Engineering
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• v.27 no.5
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• pp.738-750
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• 2022

In this study, we reviewed and discussed whether auditory stimuli with short length can evoke emotion-related neurological responses. The findings implicate that if personalized sound tracks are provided to XR users based on machine learning or probability network models, user experiences in XR environment can be enhanced. We also investigated that the arousal-relaxed factor evoked by short auditory sound can make distinct patterns in functional connectivity characterized from background EEG signals. We found that coherence in the right hemisphere increases in sound-evoked arousal state, and vice versa in relaxed state. Our findings can be practically utilized in developing XR sound bio-feedback system which can provide preference sound to users for highly immersive XR experiences.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.1
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• pp.213-218
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• 2023

In order to use the VR HMD, operation through separate controllers in both hands is required. Methods for text input in VR include a method of selecting virtual keyboard keys on the screen one by one using a controller, a method of inputting through a keyboard that is a resource of a computer by connecting a computer and VR, or a method of inputting through a keyboard that is a resource of a computer by purchasing a wireless keyboard in VR and wireless keyboard connection method. As such, the text input method in current VR equipment causes inconvenience and additional costs to users. For these reasons, most of the VR-related contents are limited to simple functions such as games or viewers, and there is a risk that VR equipment will be recognized as a simple game machine. Therefore, in this study, a multi-input interface using hand tracking provided by the Oculus Quest2 device is designed and partially implemented. Through this, it is expected that various tasks such as document work and business processing as well as games can be conveniently used using VR equipment.

• Journal of Intelligence and Information Systems
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• v.29 no.3
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• pp.341-359
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• 2023

The metaverse applies various technological means such as digital twin modeling, 3D rendering, and holographic imaging, which can provide an immersive tourism service experience. However, since the development of the metaverse is still in its infancy, there is relatively little research on digital tourism from the perspective of the metaverse. This research empirically studies the factors that promote the participation behavior of users on the metaverse platform for digital cultural tourism. Our results show that users' internal motivations for learning and entertainment and the functions provided by metaverse, which are sensory stimulation and social interaction lead to the intention to participate in cultural tourism on metaverse with the mediating effects of immersion experience and perceived pleasure.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.191-197
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• 2023

The purpose of the study was to provide an educational environment for designing and producing virtual reality practice contents that can be used in semiconductor production lines and clean rooms. Through this process, the user can acquire practical knowledge through experiences close to reality, such as experiencing the main semiconductor solar cell manufacturing facilities as well as procedural knowledge before and after entering the clean room.. In particular, it provides users with an immersion experience close to reality by creating an environment for experiential content necessary for semiconductor and solar cell manufacturing processes and clean room entrance procedure experiential content, which is expected to improve education immersion, realism, cost, efficiency, and education satisfaction. Depending on the characteristics of Dangerous, Impossible, Counter-productive etc, immersive content makes learners immersed in the learning content, induces proactive/active learning, and embodies the learning content, resulting in positive results in the field of improving educational effectiveness.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.11-11
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• 2020

18년 물관리일원화 이후 인프라와 사람 중심으로부터 자연과 인간의 조화를 위한 환경·생태계의 자연성 회복으로의 물관리 패러다임 전환이 빠르게 이루어지고 있으며, 대규모 국책사업이후의 하천 관리에 있어서도 기존의 이수, 치수, 환경이라는 단순한 기능적 구분을 벗어나 보다 근본적이고 장기적인 대국민 서비스로의 전환을 도모하고 있다. 또한, ICBAM 등으로 정의되는 4차산업혁명 기반 기술의 접목이 거의 대부분의 분야에서 이루어지고 있는 것을 실질적으로 체감하는 시기가 도래하였다. 그러나, 하천 및 수자원 관리분야에서의 기술은 근대 엔지니어링의 기초가 되는 수로 건설 등으로부터 시발되어 사실상 가장 앞선 과학적 진보의 토대를 갖추었으나 최근의 기술적 트렌드를 잘 추종하지 못하는 것처럼 비추어 지는 것이 사실이다. 주된 이유로서 기후변화라는 광범위하고 장기적인 입력요소를 가진 하천관리 시스템의 특성상 불확실성의 추정 및 즉각적인 응답이 어려운 부분이 분명히 존재하지만, 실질적으로 여전히 해소되지 않는 부분은 하천의 기초자료 수집에 대한 효율성과 신뢰도가 낮은 것이라고 하겠다. 또한, 유역으로부터 댐-다기능보-하천으로 이어지는 의사결정을 위한 다양한 형태의 자료로부터 적절한 정보를 수집하는 체계(거버넌스의 문제이자 기술적/재정적 한계)가 확립되지 않은 점도 고려해야 할 것이다. 본 연구에서는 인공지능을 활용한 하천의 유량 예측 등을 위해 필요한 수자원 기초데이터의 근원적인 수집 및 관리상의 문제점에 대해서 검토하고자 하였으며, ARIMA, Kalman Filtering, MA 및 복합기법을 통한 자료처리 기법을 적용하여 상황에 맞게 오차 및 불확실성의 저감을 위한 방안을 찾고자 하였다. 또한, 이용자 중심의 하천 관리에 근접한다고 볼 수 있는 스마트워터시티 개념에서의 바람직한 하천관리 기법에 대해서 논의하고, 관련하여 근자에 개발한 하천의 물리적 해석 도구들에 대해서 적용 사례를 검토한다. 마지막으로, 지식기반의 하천관리 의사결정 플랫폼 개발을 위해서 기존의 기계학습을 통한 자동화된 의사결정에 부가하여 전문가와 시스템이 상호작용을 통해서 AI를 학습시켜 결정한 사항을 전문가의 의사결정에 참고하는 MCRDR기법의 적용의 적용 가능성과 도입 방향에 대해서 논의하였다.

• 재활복지
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• v.14 no.3
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• pp.95-119
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• 2010

This study aims to develope participation scale of people with disabilities according to the International classification of Functioning, Disability, and Health(ICF). ICF includes a component for classifying and qualifying participation of individuals in the context of their environments. The participation scale were developed using 7 times with different focus groups using the ICIDH-2 as a contextual framework. Candidate 41 items were developed based on the 8 participation components and put into a survey format. Finally, purposeful sample of 363 people with mobility limitations was conducted survey. As a result of survey, participation scale is composed of 38 items that are placed in 7 domains used in the activity/participation component of the ICF: holisitc health; communication; mobility; domestic life; interpersonal interactions and relationships; social and economic life; civic life. This scale does not include the domains of learning and applying knowledge, general tasks and demands, recreation and leisure but more focuses on social and civic life.