• 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.

• KIISE Transactions on Computing Practices
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• v.23 no.6
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• pp.343-349
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• 2017

Combat modeling and simulation (M&S) of large-scale computer generated forces (CGFs) enables the development of even the most sophisticated strategy of combat warfare and the efficient facilitation of a comprehensive simulation of the upcoming battle. The DEVS-POMDP framework is proposed where the DEVS framework describing the explicit behavior rules in military doctrines, and POMDP model describing the autonomous behavior of the CGFs are hierarchically combined to capture the complexity of realistic world combat modeling and simulation. However, it has previously been well documented that computing the optimal policy of a POMDP model is computationally demanding. In this paper, we show that not only can the performance of CGFs be improved by an efficient POMDP tree search algorithm but CGFs are also able to conveniently learn the behavior model of the enemy through case studies in the scenario of counterfire warfare and the scenario of a mechanized infantry brigade's offensive operations.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.133-136
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• 2003

이 논문은 고리 $\#$1 원자력 발전소를 기준 발전소로 하여 개발되고 있는운전원 교육용 가상 시뮬레이터 의 일부로서, 제어봉 제어계통 모델링에 대한 내용을 제시하는 것이 주된 목적이다. 제어봉 제어 계통의 목적은 원자로 출력을 변화시키기 위하여 제어봉 집합체(RCCA)를 동작시켜 단기적인 반응도(Short Term Reactivity)를 조절하기 위한 것이다. 실제 발전소와 똑같은 제어봉 제어가 가능하면, 실제로 운전원이 가상 시뮬레이터를 통해서 모든 상황과 사고들을 대처하는 능력을 가질 수 있도록 설계되었다 본 논문에서는 고리 $\#$1 원자력 발전소 운전원 교육용 가상 시뮬레이터를 구현하기 위해 현재까지 설계된 제어봉 제어계통의 기능, 구성, 제어봉 제어에 대한 전반적인 내용을 제시하고자 한다.

• CDE review
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• v.9 no.2
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• pp.28-37
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• 2003

가상제조(VM)기술은 21세기 변화된 기업환경에서 제조경쟁력 강화를 위한 핵심기술 중에 하나로써, 형상 모델링과 시스템 이론으로 포함하여 다양한 분야로 이루어진 복합기술이다. VM 기술은 e-manufacturing의 한 분야로써 CAD/CAM 기술 발전과 궤를 같이하는데 그 적용 대상이나 방법에 따라서 digital manufacturing, virtual manufacturing, e-factory 등 다양한 이름으로 불리고 있다. 본 논문에서는 VM 기술의 개념을 정리하고, 가상제조의 국내 적용현황 및 향후 발전전망에 대하여 고찰하고자 한다.

• The KIPS Transactions:PartB
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• v.11B no.6
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• pp.683-690
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• 2004

Garment modeling and simulation is now one of the important elements in broad range of digital contents. Though there have been recent products on garment simulation, general users do not know well enough how to design a virtual costume that meets some requirements about its specific clothing pattern. In particular, Hanbok - the Korean traditional costume - has many different characteristics against western ones in the aspect of its pattern design and of draping. This paper presents a knowledge-driven approach for virtual Hanbok modeling without knowing how to make real Hanbok. First, parameterized knowledge for several fabric types art solicited using visual similarity assessment from simulated and real cloth. Secondly, based on the analysis of designer's knowledge, we defined multi-level adjustment processes of Hanbok measurements with regard to body shape features for different virtual actors. An experimental system is developed as the form of a Maya plug-in and the result shows the applicability of the proposed method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1915-1933
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• 2013

In this study, the virtual fixed point analysis and 3D fully modeling analysis for bent pile structures are conducted by considering various influencing factors and the applicability of the virtual fixed point theory is discussed. Also, the optimized column-pile length ratio is analyzed for supplementing virtual fixed point design and examining a more exact behavior of bent pile structures by taking into account the major influencing parameters such as pile length, column and pile diameter, reinforcement ratio and soil conditions. To obtain the detailed information, the settlement and lateral deflection of the virtual fixed point theory are smaller than those of 3D fully modeling analysis. On the other hand, the virtual fixed point analysis overestimates the axial force and bending moment compared with 3D fully modeling analysis. It is shown that the virtual fixed point analysis cannot adequately predict the real behavior of bent pile structures. Therefore, it is necessary that 3D fully modeling analysis is considered for the exact design of bent pile structures. In this study, the emphasis is on quantifying an improved design method (optimized column-pile length ratio) of bent pile structures developed by considering the relation between the column-pile length ratio and allowable lateral deflection criteria. It can be effectively used to perform a more economical and improved design of bent pile structures.

• Journal of Internet Computing and Services
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• v.15 no.1
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• pp.171-178
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• 2014

This paper presents dynamic modelling of a virtual object in augmented reality environments when external forces are applied to the object in real-time fashion. In order to simulate a natural behavior of the object we employ the theory of Newtonian physics to construct motion equation of the object according to the varying external forces applied to the AR object. In dynamic modelling process, the physical interaction is taken placed between the augmented object and the physical object such as a haptic input device and the external forces are transferred to the object. The intrinsic properties of the augmented object are either rigid or elastically deformable (non-rigid) model. In case of the rigid object, the dynamic motion of the object is simulated when the augmented object is collided with by the haptic stick by considering linear momentum or angular momentum. In the case of the non-rigid object, the physics-based simulation approach is adopted since the elastically deformable models respond in a natural way to the external or internal forces and constraints. Depending on the characteristics of force caused by a user through a haptic interface and model's intrinsic properties, the virtual elastic object in AR is deformed naturally. In the simulation, we exploit standard mass-spring damper differential equation so called Newton's second law of motion to model deformable objects. From the experiments, we can successfully visualize the behavior of a virtual objects in AR based on the theorem of physics when the haptic device interact with the rigid or non-rigid virtual object.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.23-29
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• 2022

Virtual humans are implemented with dedicated modeling tools like Unity 3D Engine in virtual space (virtual reality, mixed reality, metaverse, etc.). Various human modeling tools have been introduced to implement virtual human-like appearance, voice, expression, and behavior similar to real people, and virtual humans implemented via these tools can communicate with users to some extent. However, most of the virtual humans so far have stayed unimodal using only text or speech. As AI technologies advance, the outdated machine-centered dialogue system is now changing to a human-centered, natural multi-modal system. By using several pre-trained networks, we implemented an emotion-based multi-modal dialogue system, which generates human-like utterances and displays appropriate facial expressions in real-time.

• Annual Conference of KIPS
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• 2011.04a
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• pp.57-59
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• 2011

최근 컴퓨터 시스템을 소프트웨어적으로 모델링하고 시뮬레이션 성능 평가를 할 수 있는 가상 플랫폼(virtual platform) 기술이 등장하고 있다. OVPsim은 오픈 API를 제공하여 쉽게 프로세서와 주변 장치를 모델링 할 수 있는 가상 플랫폼으로서 소프트웨어 시뮬레이터이지만 매우 빠르게 실행되는 장점을 갖고 있다. 본 논문에서는 OVPsim을 사용하여 간단한 모바일 컴퓨터를 모델링하는 예를 소개하고, 모델링한 컴퓨터 플랫폼에서 리눅스 운영체제를 부팅한 결과와 벤치마크 프로그램을 통해 성능 평가를 수행한 사례를 소개한다.

• The Magazine of the IEIE
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• v.25 no.2
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• pp.40-47
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• 1998

본 원고에서 우리는 컴퓨터 그래픽스를 이용하여 가상세계 구축에 필요한 3차원 모델들을 제작하거나 애니메이션을 만드는 방법들 중에서, 사진이나 그림으로부터 비교적 손쉽게 모델을 구축하는 기술들을 분석하고 앞으로의 발전 방향에 대하여 전망하고자 한다. 이러한 기술들은 최근 들어 그 기술개발이 이루어지고 있는 분야이며 미술가가 모델링 작업에서 직접적인 역할을 담당할 수 있는 길을 열어가고 있다는 점에서 커다란 의미가 있다고 하겠다. 이러한 방법들의 핵심기술은 어떠한 것들인지를 분석해보기로 한다.