• 펄프종이기술
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• 제44권3호
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• pp.70-78
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• 2012

For evaluating the printing suitability of electronic copying papers in the aspect of climate conditions, 12 samples of copying papers being generally used in Korea and worldwide were collected. The copying papers were controlled by various temperature and humidity options in conditioning equipment in order to simulate the specific circumstances of dry, temperate or tropical climate, and the pre-heating system of photocopying machines during printing. As results, some copying papers showed several physical problems, especially in recycled copying papers and a normal paper with original printing faulty. These problems of copying papers were mostly resulted in extremely high moisture circumstance, and in lower levels of tensile strength and tensile stiffness. The moisture contents of copying papers during passing through the pre-heater system of photocopying machine could be rapidly decreased because paper is exposed to high temperature around the pre-heating zone. The copying paper, for example of XR3 sample, containing low moisture contents below 2% had high exfoliating possibility of toner transfer from copying paper.

• Restorative Dentistry and Endodontics
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• 제17권2호
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• pp.421-430
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• 1992

The purpose of this study was to evaluate the bond strength between the composite resin and light - cured glass ionomer cement base / liners treated by the several methods. The light - cured glass ionomer cement(Vitrebond / Cavalite) were injected into cavites prepared in acrylic plates. One hundred and twenty specimens were uniformly prepared and devided into 3 groups. For the first group, primer was not applied to glass ionomer cement. For the second group, no application of primer was undertaken and light - curing procedure to uncured glass ionomer cement surface which was covered by bonding agent was undertaken. After bonding composite resin to light - cured glass ionomer surface, the specimens, were stored in $37^{\circ}C$, 100% humidity for 1 hour. The following results were obtained : 1. The omission of application of a primer did not produce a significantly poorer bond strength. 2. Light - curing technique to uncured glass ionomer cement which was covered by bonding agent did not produce a significantly poorer bonding strength. 3. The bond strength of Cavalite to composite resin was significantly higher than that of Vitrebond. 4. There was no significant difference between two different types of composite materials(Silux-Plus / Herculite XR) when it was applied to bond to glass ionomer cement.

• ETRI Journal
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• 제42권2호
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• pp.258-271
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• 2020

A correlation exists between luminance samples and chrominance samples of a color image. It is beneficial to exploit such interchannel redundancy for color image compression. We propose an algorithm that predicts chrominance components Cb and Cr from the luminance component Y. The prediction model is trained by supervised learning with Laplacian-regularized least squares to minimize the total prediction error. Kernel principal component analysis mapping, which reduces computational complexity, is implemented on the same point set at both the encoder and decoder to ensure that predictions are identical at both the ends without signaling extra location information. In addition, chrominance subsampling and entropy coding for model parameters are adopted to further reduce the bit rate. Finally, luminance information and model parameters are stored for image reconstruction. Experimental results show the performance superiority of the proposed algorithm over its predecessor and JPEG, and even over JPEG-XR. The compensation version with the chrominance difference of the proposed algorithm performs close to and even better than JPEG2000 in some cases.

• 한국운동역학회지
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• 제31권4호
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• pp.249-258
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• 2021

Objective: The aim of this study was to analyze domestic and foreign studies using virtual reality or metaverse for exercise rehabilitation in order to help the disabled or elderly patients with exercise rehabilitation, and suggest a method for using metaverse for exercise rehabilitation. Method: In this study, after analyzing and discussing various information related to the metaverse and exercise rehabilitation through electronic search of recently published papers, academic journals, books, and internet websites, the exercise rehabilitation plan using the metaverse was proposed. Results: In the case of domestic research, the diversity of virtual reality application technology for the rehabilitation of disabled and elderly patients was not secured, but recently, virtual reality or metaverse-related technologies were developed and specialized in a form suitable for exercise rehabilitation. In the case of overseas studies, it was analyzed that exercise rehabilitation using virtual reality and metaverse games for the rehabilitation of disabled and elderly patients can help improve brain, physical ability, and anti-aging by activating the body and mind. Conclusion: Smart metaverse health care is actively introduced to exercise rehabilitation, metaverse telemedicine business is applied to exercise rehabilitation programs, and digital twin games and exercise rehabilitation programs developed by metaverse related companies take into account the characteristics of disabled and elderly patients. If customized smart metaverse healthcare is used for exercise rehabilitation, it is analyzed that it can lead this field.

• 방송공학회논문지
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• 제27권5호
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• pp.703-717
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• 2022

메타버스는 가상과 현실이 연결된 디지털 사회에서 사회·문화·경제 활동을 하며 다양한 가치를 생산할 수 있는 시뮬레이션 환경을 제공한다. 본 논문에서는 메타버스 서비스와 산업 현황을 분석하고 서비스 플랫폼 구현 기술들을 살펴봄으로써 그 발전 방향을 예측해 본다. 그리고, 지속가능한 메타버스를 구성하기 위한 메타버스 윤리(Metaverse Ethics)와 사용자들의 서비스 참여를 높이기 위한 메타버스 사용자경험(UX)에 대해서도 논의한다. 마지막으로, 기술 경쟁력 확보를 위해 디지털 윤리와 UX가 반영된 메타버스 R&D 추진전략을 제시한다.

• Journal of Medicine and Life Science
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• 제20권1호
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• pp.8-14
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• 2023

Interest in the metaverse is increasing as learners participate in learning with presence, improving learning motivation, and interaction. Currently, the use of metaverse in medical education remains in a test-phase of introduction within some companies, while some medical school professors are beginning to utilize it. Therefore, it is difficult to ascertain whether the metaverse has educational potential when used in medical education. This exploratory study investigates the possibility of the educational use of the metaverse. Both the educational usefulness and the examples of its educational usage in domestic and foreign medical schools are explored. As the metaverse is expected to be introduced and utilized more actively in the future, some of its advantages and limitations in medical education have been identified. In light of the vast potential of the metaverse in medical education, the method of educating and preparing medical students should be developed by preparing a new educational foundation.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1187-1193
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• 2022

A construction site is a highly complex and constantly changing environment, where hazardous areas are difficult to detect if workers lack sufficient knowledge and awareness. Thus, frequent worker safety training is required. Numerous studies on using virtual reality (VR) for safety training were published. While they demonstrate the potential for improving the skills necessary to avoid accidents in the construction industry, they remain difficult to apply at actual construction sites. VR requires specialized hardware and software, limiting workers' access and restricting workers' participation in training sessions. As a result, this paper proposes multiple platforms for immersive virtual reality safety training (VRMP) based on Industry Foundation Classes (IFC) and web technologies such as immersive web (WebXR). The VRMP is compatible with mobile and desktop devices currently by workers and demonstrates scenario models familiar to workers. Also, it reduces development time by utilizing Building Information Models (BIM). Additionally, The VRMP collects data from workers in a virtual environment to assess each worker's safety level, assisting workers in effectively and comfortably gaining a better understanding and raising their awareness. This paper develops a case study based on the VRPM in order to assess its effectiveness.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 춘계학술대회
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• pp.12-14
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• 2022

인구 고령화와 더불어 최근 10년간 치매, 경도인지장애(MCI, Mild Cognitive Disorder) 수진자 수가 19배 수준으로 급증하면서 심각한 사회·경제적 문제로 대두되고 있다. MCI는 조기 진단 및 중재를 통해 치매 예방 가능성이 가장 큰 단계이지만, 국내 치매안심센터의 물리적 수용 한계 및 팬데믹으로 인한 대면 프로그램의 중단으로 MCI 및 치매 환자의 대응이 어려운 실정이다. 본 연구에서는 향후 급증하는 노인인구와 치매 환자를 위한 인지훈련 콘텐츠의 특성을 알아보고, 고령자의 인지, 신체, 사회기능을 효과적으로 훈련할 수 있는 XR(Extended Reality) 기반의 콘텐츠 개발 고려사항을 도출하고 이를 위한 디자인 요소를 제안한다.

• 지적과 국토정보
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• 제52권2호
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• pp.103-119
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• 2022

본 연구의 목적은 재난안전 훈련의 효과성을 극대화 할 수 있는 훈련 시스템 구축 방안을 제안하는 것이다. 이를 위해 선행연구 검토 및 현황사례 분석을 통해 관련 분야별 데이터·시스템·요구기술·법·제도 등의 현재 수준을 고찰하였다. 디지털트윈과 확장현실 기술을 연계한 재난안전 훈련 시스템을 제안하였으며, 이를 위한 구축 방안 연구를 진행하였다. 본 연구의 결과물이 재난안전 훈련 시스템의 고도화에 기여하여 재난피해를 감소시킬 수 있기를 기대한다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2021년도 추계학술대회
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• pp.62-64
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• 2021

최근 코로나 19의 확산으로 인하여 코로나 감염으로 인한 외부 방송 촬영에 제약이 생기면서, 제작환경은 실외에서 실내의 가상 환경 제작 수요가 크게 증가하고 있다. 이에 확장현실 제작 기술이 방송 제작에 적극 활용되고 있다. 확장현실은 외부의 제작 환경을 몰입형 LED월 시스템 기반으로 가상의 그래픽으로 내부 스튜디오 제작환경에서 제작 할 수 있어 방송에서는 확장현실 관련 시스템 및 그래픽 콘텐츠, 운영기술 개발이 요구되고 있다. 이에 본 논문은 확장현실 콘텐츠를 제작 할 수 있는 '몰입형 혼합현실 시스템'을 제안한다. 특히, 확장현실 환경에서 원격으로 AR과 VR 콘텐츠의 동기를 맞추어 운영할 수 있도록 개발된 '원격제어 타임라인 디렉터'를 통해 AR/VR 콘텐츠를 재생 및 입출력을 제어할 수 있다. 본 시스템을 통하여 그래픽 기반의 AR/VR 시험 그래픽 콘텐츠 및 실사 기반의 360 콘텐츠 기반 확장현실 시험 콘텐츠를 개발하였으며, 상용카메라 추적시스템과 연개하어 자연스러운 추적 및 합성 그리고 타임라인 디렉터의 사용자 인터페이스를 이용하여 확장현실 콘텐츠를 제작 및 운영 할 수 있음을 확인하였다.