• Journal of Digital Convergence
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• v.11 no.12
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• pp.479-485
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• 2013

Virtualization is a promising approach to consolidating multiple online services onto a smaller number of computing resources. A virtualized server environment allows computing resources to be shared among multiple performance isolated platforms called virtual machines. Through server virtualization software, applications servers are encapsulated into VMs, and deployed with APIs on top generalized pools of CPU and memory resources. Networking and security have been moved to a software abstraction layer that transformed computing, network virtualization. And it paves the way for enterprise to rapidly deploy networking and security for any application by creating the virtual network. Stochastic reward net (SRN) is an extension of stochastic Petri nets which provides compact modeling facilities for system analysis. In this paper, we develop SRN model of network virtualization based on virtual switch. Measures of interest such as switching delay and throughput are considered. These measures are expressed in terms of the expected values of reward rate functions for SRNs. Numerical results are obtained according to the virtual switch capacity and number of active VMs.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.167-173
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• 2017

As the increasing use of the cloud computing, virtualization technology have been combined and applied a variety of requirements. Cloud computing has the advantage that the support computing resource by a flexible and scalable to users as they want and it utilized in a variety of distributed computing. To do this, it is especially important to ensure the stability of the cloud computing. In this paper, we analyzed a variety of component measurement using open-source tools for ensuring the performance of the system on the education system to build cloud testbed environment. And we extract the performance that may affect the virtualization environment from processor, memory, cache, network, etc on each of the host machine(Host Machine) and a virtual machine (Virtual Machine). Using this result, we can clearly grasp the state of the system and also it is possible to quickly diagnose the problem. Furthermore, the cloud computing can be guaranteed the SLA(Service Level Agreement).

• Journal of Digital Contents Society
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• v.14 no.4
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• pp.505-511
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• 2013

Recently, cloud computing is being emerged paradigm that a support computing resource flexible and scalable to users as the want in distributed computing environment. Actually, cloud computing can be implemented and provided by virtualization technology. In this paper, we studied open source based cloud computing and built a educational practice system through cloud computing. Virtualization-based cloud computing provides optimized computing resources, as well as easy to manage practical resource and result. Therefore, we can save the time for configuration of practice environment. In the view of faculty, they can easily handle the practice result. Also, those practice condition reuse comfortably and apply to various configuration simply. And then we can increase capabilities and availabilities of limited resources.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.83-94
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• 2016

Recent cloud, big data, there is a problem for the architectural security vulnerability to the server platforms of various fields such as artificial intelligence occurs consistently, but using the virtualization technology. In addition, most secure virtualization technology is known to be dependent on the type is limited and the platform provider. This paper presents a method for mutual authentication for secure data between multiple instances of a shared virtualized environment. The proposed method was designing a security architecture in consideration of the mutual authentication between multiple independent instances, and enhance the safety of a security protocol for sharing data by applying a key chain techniques. Performance analysis results and the existing security architecture demonstrated that protect each virtualized instances of the session and the other way, a compliance effectiveness for each instance of the mutual authentication process.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1247-1257
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• 2013

The security vulnerabilities of cloud storage virtualization environments are different from those of the existing computer system and are difficult to be protected in the existing computer system environment. Therefore we need some technical measures to address this issue. First of all, the technology used in cloud storage virtualization environment needs to be thoroughly analyzed, and also, we should understand those security requirements of various stakeholders in the view of cloud storage service and perform the research on security guidelines of the research security requirements. In this paper, we propose security requirements based on layers and roles of cloud storage virtualization. The proposed security requirements can be a basement for development of solution of cloud storage virtualization security.

• 기계와재료
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• v.23 no.1
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• pp.14-22
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• 2011

노화가 시작되면 체력이 저하되어 면역기능이 떨어져 쉽게 병에 걸리고 환경에 대한 적응력이 떨어진다. 특히 60세 이상이 되면 근육 양과 근력이 급격히 가속화되어 신체적으로 약화되기 시작한다. 노화는 자연스럽게 진행되지만 꾸준한 운동을 통해 근력 저하 속도를 늦출 수 있다. 근력 증강을 위한 다양한 기기 개발에도 불구하고 노인들이 사용하는데 어려움이 있다. 특히 노인 신체적 특성에 맞는 운동기기 개발이 절실하며, 노인의 흥미를 유발시켜 자발적 참여를 유도하는 환경이 제공되어야 한다. 가상현실 기술은 실재하지 않거나 먼 거리에 있는 환경을 가상세계로 생성시켜서, 인간의 오감을 각종 인터페이스 장치를 통해 신호를 전달하여 가상의 현실 환경에 실재하고 있다고 느끼도록 만들어 주고, 가상세계와 상호작용을 통해 의료 진단, 치료, 재활 등에 유용한 도구 및 환경을 제공한다. 이러한 가상현실 기술의 특성 때문에 노인의 운동 참여와 운동 효과를 극대화 할 수 있다. 본 논문에서는 근력의 특성을 분석하고 노화와 근력과의 관계를 조사하고, 상지근력 증강 운동기와 해당 가상현실 컨텐츠 그리고 관련 컨텐츠 개발 동향에 대해 제시하고자 한다.

• Information Systems Review
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• v.24 no.4
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• pp.119-142
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• 2022

Organizations are attempting a digital transformation that converts physical business processing into virtual business processing. Through this digital transformation, organizations are overcoming time and space constraints and creating competitiveness. The digital transformation of this work environment has been accelerated as many organizations have implemented remote work due to the recent COVID-19 pandemic. This study focused on business process virtualizability, which is the result of the rapid digital transformation of the work environment. Business process virtualizability is the resulting quality, such as the suitability or excellence of business processing in a virtual environment. This research model is the effect of process, IT and organizational characteristics on business process virtualizability. As a result of the verification of people who have experienced remote work in a virtual environment, first, it was confirmed that, in terms of process characteristics, sensory requirements affect business process virtualizability, but relationship requirements, synchronism requirements, and identification and control requirements do not. Second, in terms of IT characteristics, it was confirmed that representation and reach affect business process virtualizability. Third, it was confirmed that, in terms of organizational characteristics, job autonomy affects business process virtualizability, but evaluation unfairness does not. This study found that representation and reach of IT had the most significant influence on business process virtualizability, job autonomy was next, and sensory requirements had the lowest influence. This presents practical implications for organizations to increase the success potential of business process virtualizability.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.1
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• pp.86-96
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• 2016

Recently, virtualization is becoming the critical issue in the cloud computing due to its advantages of resource utilization and consolidation. In order to efficiently use virtualization services, several issues should be taken into account, including data reliability, security, and performance. In particular, a high write bandwidth on the virtual machine must be guaranteed to provide fast responsiveness to users. In this study, we implemented a way of visualizing comparison results between the block write pattern of KVM-based virtual machine and that of the real machine. Our final objective is to propose an optimized virtualization environment that enables to accelerate the disk write bandwidth.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.113-114
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• 2019

클라우드 환경에서는 가상머신의 고성능 연산을 지원하기 위해 Graphic Processing Unit(GPU)를 사용한다. 가상머신들은 공평성을 위해 독립적인 가상머신 스케줄러를 사용하기 때문에 컴퓨팅 자원의 초과 사용으로 인한 성능 저하가 발생해도 동일한 작업을 수행하는 가상머신들의 성능은 균등하게 측정된다. 하지만 GPU 연산의 경우 다중 작업을 수행할 때 하드웨어 기반 스케줄러를 사용하며 가상머신의 입출력 작업을 위한 하이퍼바이저의 First In First Out(FIFO) 기반 스케줄링 기법으로 인해 가상머신 사이의 공평성을 보장할 수 없다. 본 논문에서는 GPU 메모리를 초과 사용하는 환경에서 가상머신들의 성능을 측정하고 성능 불균형으로 인한 문제를 분석한다.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.9
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• pp.916-920
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• 2008

The personal workspace consists of user- specified computing environment such as user profile, applications and their configurations, and user data. Mobile computing devices (i.e., cellular phones, PDAs, laptop computers, and Ultra Mobile PC) are getting smaller and lighter to provide personal work-space ubiquitously. However, various personal work-space mobility solutions (c.f. VMWare Pocket ACE[1], Mojopac[2], u-PC[3], etc.) are appeared with the advance of virtualization technology and portable storage technology. The personal workspace can be loaded at public PC using above solutions. Especially, we proposed a framework called ubiquitous personal computing environment (u-PC) that supports mobility of personal workspace based on wireless iSCSI network storage in our previous work. However, previous u-PC could support limited applications, because it uses IRP (I/O Request Packet) forwarding technique at filter driver level on Windows operating system. In this paper, we implement OS-level virtualization technology using system call hooking on Windows operating system. It supports personal workspace mobility and covers previous u-PC limitation. Also, it overcomes personal workspace loading overhead that is limitation of other solutions (i.e., VMWare Pocket ACE, Mojopac, etc). We implement a prototype consisting of Windows XP-based host PC and Linux-based mobile device connected via WiNET protocol of UWB. We leverage several use~case models of our framework for proving its usability.