• Journal of Korea Game Society
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• v.12 no.3
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• pp.69-76
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• 2012

At MMORPGs that has the numerous game users with many interactions at the same virtual world, massive loading that results in delays, resource shortages, and other such problems occur. To solve this, many developers devote research to load-balancing servers, yet due to steady and dynamic map divisions, such research is unreliable. This paper proposes a game user-oriented load balancing scheme for the load balancing of MMORPG servers. This scheme shows effectiveness at dealing with hot-spots and other gatherings of game users at specific servers compared to previous methods.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.454-461
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• 2010

The new SOLAS regulation permits the alternative design approach for the approval of designs which deviate from those where prescriptive rules apply. The new approach is being promoted by recent advances of noble designs such as those employing large public spaces in passenger ships. From the respect of fire safety, it is needed to show that the level of safety of new design is equivalent to what can be achieved from the prescriptive rules where the fire simulation is regarded to be the essential tool. This paper provides an overview of the process of performance-based design of the smoke extraction system in a cafeteria of a ROPAX. FDS, a CFD fire simulation software is used to show that the field-model software can improve the fire safety over what are expected from prescriptive rule sets or zone-model application.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.2 s.152
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• pp.83-92
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• 2007

To improve the fire safety of ships, it is required to prepare the systematic design guideline for fire protection and the way of assessing fire characteristics quantitatively. The introduction of simulation technique based on fire engineering is useful to assess fire safety performance quantitatively. Fire simulation tools are currently developing with U.S.A., Europe and Japan as a leader. Most of current fire simulation tools were developed for building or inland structure. Therefore it is required validation process and development of data base to apply maritime environments. In this paper, I/O parameters of simulation tools such as CFAST and BRI2002 of zone model and FDS and KFX of field model analysed, and designed data base considering maritime environment. The fire simulation for the pool fire model of engine room and its adjacent compartments is performed and evaluated the results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.785-788
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• 2012

최근 B2C 서비스산업에 있어 기업 간의 경쟁이 심화되고 새로운 비즈니스 가치 창출을 위한 필요 성이 증대되고 있는 상황에서, 기업들은 비즈니스 프로세스 관리 기술에 많은 관심을 기울이고 있다. 프로세스의 최적화를 통해 지속적으로 서비스 품질을 개선하기 위해 비즈니스 프로세스 재설계의 근거로 사용될 수 있는 비즈니스 프로세스 마이닝이 중요한 개념으로 인식되고 있다. 하지만 기존의 프로세스 마이닝에 관한 연구에서는 완성되어 있는 프로세스 로그를 기반으로 워크플로우 기반의 프 로세스 모델을 추출하는 단조로운 형태였기 때문에 다양한 형태의 비즈니스 프로세스를 표현하는데 한계가 있었다. 본 논문에서는 컨벤션, 대학,병원등 광범위한 지식서비스 분야에서 적합한 Prototype 기관을 Test bed로 다양한 프로세스 마이닝 기법으로 분석하여 해당 조직의 문제 프로세스를 발견하 고 개선점을 제안하다. 또한 B2C 서비스 산업에서 적절한 Test bed를 선정하여, 실제 프로세스를 기 존의 legacy system의 event log file에서 분석하여 bottle neck process를 찾아내고, 문제 프로세스를 개선하는 과정을 자동화된 모델링 및 분석 툴을 사용하여 실증적으로 보여준다.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.810-817
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• 2007

Every ports is making great efforts to get competitiveness. It is progressing for the research on port model of new concept that connect port-related business to be developed from base running simple cargo processing to universal port that has economical efficiency and competitiveness, This research shows development way of Busan port that connect ship-repair industry which is port-related business. Development way is especially handled link between port and ship-repair industry field activation of high value-added ship as LNG etc.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.717-720
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• 2002

본 논문은 주성분분석(Principal Component Analysis, PCA)을 통하여 실시간 얼굴 검출 및 추적 방법을 제안한다. 제안된 방법은 얼굴 영역 검출과 추적의 두 단계로 구성되어 있다. 검출 단계에서는 피부색깔 모델과 움직임 정보를 이용하여 얼굴 후보 영역들을 검출하고, 검출된 후보 영역들을 주성분 분석을 통하여 검증한다. 추적 단계에서는 검출된 얼굴들 중에서 현재 추적 중인 얼굴과 가장 유사한 얼굴을 찾아 전체 영상의 중심에 위치하도록 pan/tilt 위에 놓여진 카메라를 제어하여 추적한다. 제안된 방법은 잡음이 많은 배경 상황에서도 존은 실험 결과를 보여준다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.722-723
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• 2015

스마트 기기의 확산으로 인해, 보다 다양한 애플리케이션이 개발되고 있다. 증강현실 기법 역시 이미지를 마커로 활용할 수 있게 발전됨에 따라, 광고나 전시 등에서 많이 활용되고 있다. 구현된 포토시스템은 이미지 인식 기반으로 하여, 3D모델과 함께 사진을 찍을 수 있다. 세종문화회관에서 개최된 콘텐츠 전시회에서는 로고 이미지를 이동이 용이한 폼에 부착하여 활용함으로서 브랜드 광고효과도 볼 수 있었다. 본 연구는 스마트 기기를 이용하여, 전시장에서 색다른 포토존 서비스를 제공함으로서, 증강현실 콘텐츠의 새로운 활용 사례를 제시하였다.

• Journal of Korean Society of Steel Construction
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• v.20 no.5
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• pp.617-624
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• 2008

Well-designed steel moment connections will undergo local buckling before they exhaust their available rotation capacity, and inelastic post-buckling deformation plays a major role in defining the connection rotation capacity. An approximate analytical method to model strength degradation and failure of beam plastic hinges due to local buckling and estimation of the seismic rotation capacity of fully restrained beam-column connections in special steel moment-resisting frames under both monotonic and cyclic loading conditions is proposed in this study. This method is based on the plastic mechanism and a yield line plastic hinge (YLPH) model whose geometry is determined using the shapes of the buckled plastic hinges observed in experiments. The proposed YLPH model was developed for the improved WUF-W and RBS connections and validated in comparison with experimental data. The effects of the beam section geometric parameters on the rotation capacity were discussed in the companion paper (parametric studies).

• Tunnel and Underground Space
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• v.13 no.4
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• pp.287-293
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• 2003

A long vertical duct is an essential installation for extracting smoke to the ground level when a fire occurs in an underground space. Due to the limitations of its basic assumptions, the existing two-layer zone model is unsuitable to model smoke dispersion through a long vertical duct. Therefore, an assessment was made to investigate the applicability of the field model, which is based on the computational fluid dynamics (CFD). A similar configuration to the published experimental work was modeled to test the validity. It is clear that under a consistent decision criterion based on the mass fraction, the field model (CFD) is able to predict that the diffusion front progresses up the shaft with exactly the same rate as that in the empirical correlation equation. This result is for better than the mathematically obtained equations in previously published research. Therefore, it can be said that the field model is an excellent option to predict the smoke dispersion through the long vertical shaft.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.5
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• pp.416-422
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• 2016

This paper presents preliminary performance analysis of a satellite formation flying testbed, which is under development by Astrodynamics and Control Laboratory, Department of Astronomy, Yonsei University. A model reference adaptive controller (MRAC) with a first-order reference model is chosen to enhance the response of reaction wheel system which is subject to uncertainties caused by unmodelled dynamics and measurement noise. In addition, an on-line parameter estimation (OPE) technique based on the least square is combined to eliminate the effect of angular measurement noise by estimating the moment of inertia. Both numerical simulations and hardware experiments with MRAC support the effectiveness and applicability of the adaptive control scheme, which maintains the tracking error below $0.25^{\circ}$ for the entire time span. However, the high frequency control input generated in hardware experiment strongly suggests design modifications to reduce the effect of deadzone.