• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.23-29
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• 2023

As an effort to maximize the immersiveness of user experience in virtual reality, there have been constant efforts to provide a user with tactile sensation by providing haptic feedback. Most of the haptic feedback methods, however, can create only limited or unrealistic haptic sensations since they utilize affordable actuators such as a vibrotactile actuator. When it comes to martial arts training or a game, the limitation of such haptic feedback is apparent due to the significant difference between the physical impact of hitting an object and the sensation departed from a vibrotactile actuator. Noting this, we proposed a haptic impact system that can create a haptic impact when the user hits a virtual object with the fist. The haptic interface uses a quick-return mechanism that can deliver haptic impact feedback to a user's fist. The realism of the haptic impact was evaluated by conducting a human-subject experiment. The results indicate a significant effect of haptic feedback on the realism of the virtual impact.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.775-782
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• 2023

In order to overcome practical limitations in installing, managing and operating MRI machines with expensive equipment, this study developed and utilized virtual reality (VR) experience education by combining virtual reality (VR) with magnetic resonance imaging devices. The Students who experienced virtual reality-based educational systems were surveyed to identify possible side effects during the experience and self-directed learning ability and academic self-efficacy surveys were conducted to analyze the impact of virtual reality-based practice on learning. In the analysis of the self-directed learning ability survey there was no difference in the average between the student group who experienced education and the student group who did not but there was a significant difference in the average for each group. Virtual Reality-based practical education is expected to provide an efficient practice system by providing new learning methods and opportunities for education that can be repeated anytime, anywhere regardless of time and space.

• Journal of Internet Computing and Services
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• v.25 no.1
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• pp.9-15
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• 2024

As virtual reality technology became popular, a high demand emerged for natural and efficient interaction with the virtual environment. Mid-air manipulation is one of the solutions to such needs, letting a user manipulate a virtual object in a 3D virtual space. In this paper, we focus on manipulating a remote virtual object while visually displaying the object and providing tactile information on the object's weight. We developed two types of wearable interfaces that can provide cutaneous or vibrotactile feedback on the virtual object weight to the user's fingertips. Human perception of the remote virtual object weight during manipulation was evaluated by conducting a psychophysics experiment. The results indicate a significant effect of haptic feedback on the perceived weight of the virtual object during manipulation.

• Journal of the Korea Society of Computer and Information
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• v.29 no.7
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• pp.1-9
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• 2024

In this paper, we propose BRAIDS, a boot storm mitigation plan consisting of an AI-based VDI usage prediction system and a virtual machine boot scheduler system, to alleviate boot storms and improve service stability. Virtual Desktop Infrastructure (VDI) is an important technology for improving an organization's work productivity and increasing IT infrastructure efficiency. Boot storms that occur when multiple virtual desktops boot simultaneously cause poor performance and increased latency. Using the xgboost algorithm, existing VDI usage data is used to predict future VDI usage. In addition, it receives the predicted usage as input, defines a boot storm considering the hardware specifications of the VDI server and virtual machine, and provides a schedule to sequentially boot virtual machines to alleviate boot storms. Through the case study, the VDI usage prediction model showed high prediction accuracy and performance improvement, and it was confirmed that the boot storm phenomenon in the virtual desktop environment can be alleviated and IT infrastructure can be utilized efficiently through the virtual machine boot scheduler.

• Smart Media Journal
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• v.12 no.11
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• pp.86-94
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• 2023

In recent years, advertisements and brand promotions using virtual influencer have been actively conducted, and this study focused on the characteristics of virtual influencer, including Attractiveness, to examine the Attractiveness of virtual influencer through previous studies and to test the hypothesis that Attractiveness has an effect on Brand attitude and Advertising attitude when mediated by Immersion. For this purpose, data were collected from university students who experienced marketing contents using virtual influencer, and Process macro was conducted to analyse the mediating effect. The results showed that virtual influencer Attractiveness partially mediated the relationship between Brand attitude and Advertising attitude. These results suggest that virtual influencer Attractiveness not only affects Brand attitude and Advertising attitude, but also positively increases consumer attitude when mediated by Immersion. This study has both academic and practical implications by examining the mediating effect of Immersion on the effect of virtual influencer Attractiveness on consumer attitudes.

• Convergence Security Journal
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• v.24 no.3
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• pp.51-57
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• 2024

Cryptocurrency service providers and virtual asset operators, built on blockchain technology, face transaction risks such as cyber threats, wallet theft by internal personnel, theft of customers' private keys, and fraudulent cryptocurrency transfer signatures. To ensure secure operations against these threats, their security is validated through the ISMS-P certification. This study to analyze the risks presented in ISO TR 23576, which is specialized for cryptocurrency service providers and operators, in addition to the ISMS-P certification they obtain. The study will focus on the detailed inspection items of ISMS-P and ISO TR 23576 for cryptocurrency service providers and assess their importance. Based on this analysis, the study proposes an internal security control process for cryptocurrency service providers to address the top-priority risks, enabling practitioners to perform security control tasks more efficiently.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06a
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• pp.293-295
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• 2012

가상화 기술은 물리적 컴퓨팅 자원을 사용자에게 논리적으로 제공하여 시스템의 효율성을 높이고 유연성을 향상시키기 위한 기술로 서버 통합이나 아마존 EC2와 같은 클라우드 컴퓨팅 환경에서 사용되고 있다. 이러한 가상화 환경에서는 다수의 가상머신들의 동시적인 I/O 수행으로 인해 저장장치에 병목현상이 발생된다. 또한 각 가상머신들의 중복된 데이터들을 저장하기 위해 불필요한 쓰기 비용이 발생하여 시스템의 성능 저하가 발생하게 된다. 본 논문에서는 이러한 가상화 환경에서의 I/O비용을 감소시키기 위해 SSD를 캐시로 사용하는 중복 제거 기법을 제안한다. 제안된 기법은 중복된 데이터를 제거하여 불필요한 디스크에 대한 I/O 수행을 감소시키며, 중복 발생 패턴의 특성을 고려하여 SSD의 빠른 쓰기 성능을 효과적으로 사용할 수 있는 캐시 구조 모델을 통해 가상화 환경에서 I/O 성능을 향상 시킬 수 있음을 보인다.

• KIPS Transactions on Computer and Communication Systems
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• v.4 no.9
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• pp.315-320
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• 2015

In cloud computing, server virtualization supports one or more virtual machines loaded on multiple operating systems on a single physical host server. Migration of a VM is moving the VM running on a source host to another physical machine called target host. A VM live migration is essential to support task performance optimization, energy efficiency and energy saving, fault tolerance and load balancing. In this paper, we propose open source based adaptive VM live migration technique. For this, we design VM monitoring module to decide VM live migration and open source based full-virtualization hypervisor.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1069-1074
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• 2006

자동차/선박/정보통신기기 등의 각종 제조 산업 분야에서 신제품 개발기간과 비용단축을 위해 제품의 설계/스타일링 단계에서 디자인 및 사용자 사용성/편이성 등에 대해 가상으로 품평하는 기술에 대한 관심이 날로 증가하고 있다. 이상적인 가상 품평 기술은 사용자가 실물에 대한 품평 상황과 동일한 체험을 얻을 수 있도록 해야 한다. 이를 위해서 품평 대상물을 사실적으로 표현할 수 있도록 하는 실사 수준의 고품질 가시화 기술과 사용자가 품평 대상물을 자연스럽게 조작할 수 있는 상호작용 기술이 필요하다. 본 연구는 자동차의 내 외관 디자인 품평을 위한 가상 디자인 품평 시스템의 개발에 관한 것으로, 사실적인 자동차 가시화를 위한 환경 반사, 빛 산란, 범프 매핑등의 고품질 쉐이더 구현 및 저작 기술, 몰입환경에서 품평 작업을 위한 3D GUI 지원, 자동차 각 부품의 사용성/편이성 평가를 위한 운동성 조작 기능, 멀티프로젝션 디스플레이 시스템 및 3 차원 인간 모델, 장갑형 입력장치 지원을 통한 몰입형 가상 품평 환경 구축에 관한 기술 및 구현 방법을 제시하고자 한다.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.118-123
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• 2006

본 논문에서는 반몰입형 가상현실 시스템인 반응형 멀티미디어 시스템(RMS: Responsive Multimedia System)을 이용한 개인화된 스토리텔링 기법을 제안한다. 인간은 글, 그림, 영상 기술 등을 이용한 다양한 스토리텔링 기법을 개발해 왔으며, 가상 현실 기술을 통하여 기존의 멀티미디어보다 한차원 높은 수준의 스토리텔링을 가능하게 하였다. 제안된 스토리텔링 기법은 테이블 형태의 다감각 사용자 인터페이스, 사용자 정보 처리와 위치기반 이벤트를 결정하는 컨텍스트 인식 응용 모델 (vr-UCAM), 그리고 가상환경 네비게이션과 변화, 캐릭터의 애니메이션을 가능케 하는 가상공간 관리기로 구성된다. 제안된 스토리텔링 기법은 다감각 사용자 인터페이스를 통하여 직관적인 상호작용을 가능하게 한다. 그리고 컨텍스트 인식 응용 모델을 활용하여 사용자 개인정보를 스토리에 적용하여 개인화된 스토리가 전개될 수 있도록 한다. 그리고 가상 환경의 네비게이션, 가상 캐릭터, 날씨 및 환경의 변화 등을 조절하여 실감있게 스토리가 전개되도록 한다. 제안된 스토리텔링 환경을 검증하기 위해 운주사에 얽힌 설화를 기반으로 가상 운주사 체험 시스템을 구현하였다. 이를 통해, 반응형 멀티미디어 시스템을 이용한 스토리텔링의 가능성을 검증하였으며, 컨텍스트 인식 응용 모형을 활용한 개인화된 스토리텔링을 선보였다. 제안된 스토리텔링 기법은 문화교육, 에듀테인먼트, 예술 분야에 활용될 것으로 기대된다.