• Journal of KIISE:Computer Systems and Theory
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• v.37 no.1
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• pp.35-42
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• 2010

Guest operating systems running over the virtual machines share a variety of resources. Since CPU is allocated in a time division manner it consequently leads them to having the unknown physical time. It is not regarded as a serious problem in the server virtualization fields. However, it becomes critical in embedded systems because it prevents guest OS from executing real time tasks when it does not occupy CPU. In this paper we propose a hypercall to register a timer service to notify the timer request related real time. It enables hypervisor to schedule a virtual machine which has real time tasks to execute, and allows guest OS to take CPU on time to support real time. The following experiment shows its implementation on Xen-Arm and para-virtualized Linux. We also analyze the real time performance with response time of test application and frames per second of Mplayer.

• KIISE Transactions on Computing Practices
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• v.24 no.3
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• pp.122-128
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• 2018

In recent years, virtual training has attracted a lot of attention because it is as effective as traditional in-person training and provides more cost-effective and safer learning environment. However, the existing virtual training systems rely on the evaluator's qualitative judgement when evaluating and analyzing trainees' performance. Additionally, evaluation and analysis functions are only available on certain systems so those functions need to be developed for each system. In this paper, we propose an extensible evaluation and analysis system for virtual training using experiential knowledge collected from experts for providing effective evaluation and analysis. Specifically, we provide a method of applying Open API so that the proposed system works with different types of virtual training system. In addition, the experiential knowledge is constructed in advance for the evaluation and analysis so that the efficiency of the evaluation with the comparison target is increased. This experiential knowledge can be quantitatively compared to trainees' performance according to the proposed evaluation and analysis procedures.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.6
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• pp.358-366
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• 2006

This paper describes a novel navigation algorithm using a locomotion interface with two 6-DOF programmable foot platforms. When a human walks on the locomotion interface (LI), the walking motions of the human are recognized by several sensors. Then, the sensed information is used by the LI for generation of infinite surfaces for continuous walking and the virtual environments for scene update according to motions of the human walking. The suggested novel navigation system can induce user's real walking and generate realistic visual feedback during navigation. A novel navigation algorithm is suggested to allow natural navigation in virtual environments by utilizing conditions of normal gait analysis. For realistic visual feedback, the virtual environment is designed with three components; 3D object modeler for buildings and terrains, scene manager and communication manager component. From experiments, the subjects were satisfied with the reality of the suggested navigation algorithm using the locomotion interface. Therefore, the suggested navigation system can allow a user to explore into various virtual terrains with real walking and realistic visual feedback.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.800-801
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• 2011

최근 건강-의료 분야의 학과 신설 및 전공자가 급격하게 늘어남에 따라 해부학 교육의 질적 향성 및 학습자의 학습효과 증진을 도모하기 위해서는 새로운 강의방식의 도입이 필요하다. 따라서 본 연구는 해부학 교육에 있어 면대면 강의에 사용한 내용을 바탕으로 가상강의 컨텐츠를 자체개발하였고, 2007-2009년 간호학과 및 스포츠과학부의 전공필수 과목인 해부학 강의를 가상강의 방식으로 실시하였다. 이 과목을 수강한 2개 학과 231명을 대상으로 강의 종료 후 가상강의실 게시판 및 컨텐츠 활용 빈도, 개별 설문조사, 학기말 성적을 확보하여 가상강의실 활용도, 만족도 및 학업성취도 상호간의 상관관계를 분석하였다. 학생들의 만족도, 난이도, 흥미도, 평가의 적절성, 전공연계성 등에서 긍정적인 평가를 받았다. 또한 가상강의실의 로그인 횟수와 게시판에 대한 학생들의 만족도가 높게 나타났다. 학업성취도는 난이도 (r=0.411, p<0.01)와 높은 상관관계를 나타내었고, 만족도-흥미도(r=0.407, p<0.01), 만족도-전공연계성 (r=0.507, p<0.01), 흥미도-전공연계성 간에도 높은 상관관계를 보였으나 흥미도-전공연계성(r=0.474, p<0.01) 등에서 높은 상관관계를 나타내었다. 결론적으로 본 연구를 통해 건강-의료 분야의 전공자뿐만 아니라 다양한 분야에서 폭넓게 요구하고 있는 해부학 강의수요를 효과적으로 흡수함과 아울러 해부학교육에 있어 새로운 지평을 열수 있는 가상강의에 대한 연구로서, 향후 해부학 교육에 있어 충분한 활용가치가 있는 효과적인 교수법이 될 것으로 사료된다.

• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.182-190
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• 2007

Virtual world is the 3D graphical interactive environment that networked by electronic communications. Virtual Worlds offered flow experience for a long time to their users. They blur the boundaries of work and play, so bring out the concept of Fun Labor. If we can accept the principle of equivalence between Fun Labor and Real Labor, the Fun Labor may be one of the solutions of the large unemployment problem in the information society. And the Fun Labor is the new type of labor that corresponds the subjectivity of users who want interesting experience as much as they spend money and times. This situation means that the users of Virtual worlds are structuring the identities as the Residents who act the Fun Labor. It'll be very important to examine the social effects of this situation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.199-212
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• 2014

This paper describes an autonomous air combat guidance law using a Virtual Pursuit Point (VPP) in one-on-one close engagement for Unmanned Combat Aerial Vehicle (UCAV). The VPPs that consist of virtual lag and lead points are introduced to carry out tactical combat maneuvers. The VPPs are generated based on fighter's aerodynamic performance and Basic Fighter Maneuver (BFM)'s turn circle, total energy and weapon characteristics. The UCAV determines a single VPP and executes pursuit maneuvers based on a smoothing function which evaluates probabilities of the pursuit types for switching maneuvers with given combat states. The proposed law is demonstrated by high-fidelity real-time combat simulation using commercial fighter model and X-Plane simulator.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.9
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• pp.103-108
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• 2014

In the virtualized server systems, a scheduler in a hypervisor is responsible to assign physical resources for virtual machines. However, the traditional scheduler is hard to provide optimized resource allocation considering the amount of I/O requests. Especially, the drawback hinders performance of software load balancer which runs on virtual machines to distribute I/O requests from the clients. In this paper, we propose a new architecture to improve the performance of software load balancer using multiprocess. Our architecture aims to improve hardware resource utilization and overall performance of the server systems which utilize virtualization technology. Experimental results show the effectiveness of the proposed architecture for the various cases.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.1-7
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• 2017

Virtual reality(VR) is known as immersive multimedia or computer-simulated reality, is a computer technology that replicates an environment, real or imagined, and simulates a user's physical presence and environment to allow for user interaction. Virtual realities artificially create sensory experience including sight, touch, hearing, and smell. Owing to the use of a single device in most VR contents, user have difficulty in manipulating user interface and game object. And also immersion of the game goes down because they can't see the mouse and keyboard in virtual space. In this paper, we design and implement the chess game to easily and accurately control user interface to improve the immersion in game.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.317-323
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• 2018

Although various kinds of VR services are being carried out in the tourism field, The virtual reality experiences are still costly, since they could be realized in a limited space with some kinds of expensive equipment such as HMD. In this study, we propose a mobile virtual reality tourism experience using an easy and simple Google card board and user's smartphone because most tourist sites are outdoors and most of users like enjoying sightseeing and experience at the same time. For this purpose, we constructed a system that provides tourist information in real time employing both the IoT and VR techniques. Especially we develpoed a tourism contents for the UNESCO World Heritage Communities of Baekje Historical Site and Songsanri Tumulus. In addition, we virtually restored the royal palace in Gongju and confirmed the historical experience by VR flatform could be popular with people.

• The Journal of the Korea Contents Association
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• v.12 no.5
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• pp.91-102
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• 2012

Virtual Advertising and Product Placement which had been brought up to strengthen the competitiveness of the contents and vitalize the Advertising Industry, especially broadcasting advertising were finally adopted. This is a study to review what the background and the current condition of the virtual advertising and product placement are, identify what their current and potential problems are, and discuss how to settle the issues and make improvements. It also presents an empirical study on audience awareness. As a result of the study, audience tends to show high awareness of virtual advertising and product placement, to accept them more positively and show higher reliability of them than any other advertising. Moreover, it appears that they pay more attention to them, express their favor on them, and regard them convincing. This is an important point to both academic field and industry, which is likely to give suggestions to establish policy for virtual advertising and product placement and to develop broadcasting advertising in the future.