• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 KOBA 방송기술 워크샵 KOBA Broadcasting Technology Workshop
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• pp.201-206
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• 1999

Though a demand for 3-D CG (Three-Dimensional Computer Graphics) drastically increases, traditional modeling system for virtual objects are very difficult to handle. Applying VR (Virtual Reality) technology is, however, able to make the modeling systems more efficiently and intuitively. In this paper, traditional modeling operations are analyzed and their problems are clarified. We discuss what can be improved with VR technology. Then, a guideline of merging VR technology into the modeling system is described. A new modeling system is proposed using a CAVE system which is utilized in the latest VR technology. This proposed system aids in creating 3-D objects with high immersion in VEs (Virtual Environments)

• 한국정밀공학회지
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• 제14권2호
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• pp.136-144
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• 1997

Usually triangular patches are used to transfer geometric shape in Rapid Prototyping CAM system. STL, a list of triangles, is de facto standard in RP industry. Because STL does not have topological infoma- tion, it can cause errornous results. So STL should be verified before using. After adding support structures to anchor the part to the platform and to prevent sagging or distortion, slicing and layer by layer manufactur- ing process are done. But triangular patch is surface model and cannot provide sufficient information on geometry in the above processes. So, geometric modeling is necessary in verifying STL, adding support structures and slicing. It is natural that triangle based modeling is the best when tringular patches are used as input. Considering support structures, solid and faces coexist in RP process. Therefore non-manifold modeler is required. In this study, triangle based non-manifold geometric modeling is proposed for RP sys- tem consistent with STL input.

• Journal of Information Processing Systems
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• 제14권3호
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• pp.569-589
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• 2018

Cloud computing, also known as "country as you go", is used to turn any computer into a dematerialized architecture in which users can access different services. In addition to the daily evolution of stakeholders' number and beneficiaries, the imbalance between the virtual machines of data centers in a cloud environment impacts the performance as it decreases the hardware resources and the software's profitability. Our axis of research is the load balancing between a data center's virtual machines. It is used for reducing the degree of load imbalance between those machines in order to solve the problems caused by this technological evolution and ensure a greater quality of service. Our article focuses on two main phases: the pre-classification of tasks, according to the requested resources; and the classification of tasks into levels ('odd levels' or 'even levels') in ascending order based on the meta-heuristic "Bat-algorithm". The task allocation is based on levels provided by the bat-algorithm and through our mathematical functions, and we will divide our system into a number of virtual machines with nearly equal performance. Otherwise, we suggest different classes of virtual machines, but the condition is that each class should contain machines with similar characteristics compared to the existing binary search scheme.

• 대한원격탐사학회지
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• 제37권1호
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• pp.161-167
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• 2021

This paper presents the method to quantitatively evaluate the uncertainty of the semi-empirical Bidirectional Reflectance Distribution Function (BRDF) model for Himawari-8/AHI. The uncertainty of BRDF modeling was affected by various issues such as assumption of model and number of observations, thus, it is difficult that evaluating the performance of BRDF modeling using simple uncertainty equations. Therefore, in this paper, Monte-Carlo method, which is most dependable method to analyze dynamic complex systems through iterative simulation, was used. The 1,000 input datasets for analyzing the uncertainty of BRDF modeling were generated using the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) Radiative Transfer Model (RTM) simulation with MODerate Resolution Imaging Spectroradiometer (MODIS) BRDF product. Then, we randomly selected data according to the number of observations from 4 to 35 in the input dataset and performed BRDF modeling using them. Finally, the uncertainty was calculated by comparing reproduced surface reflectance through the BRDF model and simulated surface reflectance using 6S RTM and expressed as bias and root-mean-square-error (RMSE). The bias was negative for all observations and channels, but was very small within 0.01. RMSE showed a tendency to decrease as the number of observations increased, and showed a stable value within 0.05 in all channels. In addition, our results show that when the viewing zenith angle is 40° or more, the RMSE tends to increase slightly. This information can be utilized in the uncertainty analysis of subsequently retrieved geophysical variables.

• 한국습지학회지
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• 제14권3호
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• pp.353-363
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• 2012

4대강살리기사업을 통해 건설된 수리구조물의 효과적 운영과 홍수기 피해저감을 위해서는 적절한 의사결정 지원시스템의 구축이 필수적이다. 본 연구에서는 기존 일차원모의를 통한 하천관리의 한계를 보완하기 위하여 수문관측자료 또는 1차원모의 결과를 이용한 2, 3차원 모형 연계모의가 가능한 시스템을 개발하였다. 기존의 1차원 수리, 수문 모형으로 제공받던 선단위 지점단위 정보 뿐 아니라 추가적으로 공간 격자단위 정보를 제공받을 수 있는 다차원 모의를 수행함으로써 하천에서의 물리적 현상을 적절히 고려한 공간적 수리특성을 반영한 하천관리가 가능할 것이다. 급격한 지형변화 및 수리구조물에 의한 홍수에 대비하고 각 격자별 유량의 전달에 의한 홍수파의 전파양상에 대한 공간단위 정보를 토대로 합리적인 하천관리를 위한 기초자료로 활용될 수 있을 것으로 판단된다.

• Smart Structures and Systems
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• 제13권3호
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• pp.407-418
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• 2014

The purpose of this paper is to present an Integrated Life Cycle Bridge Information Modeling that can be used throughout different phases of the bridge life cycle including: design, construction, and operation and maintenance phases. Bridge Information Modeling (BrIM) has become an effective tool in bridge engineering and construction. It has been used in obtaining accurate shop drawings, cost estimation, and visualization. In this paper, BrIM is used as an integrated tool for bridges life cycle information modeling. In the design phase, BrIM model can be used in obtaining optimum construction methods and performing structural advanced analysis. During construction phase, the model selects the appropriate locations for mobile cranes, monitors the status of precast components, and controls documents. Whereas, it acts as a tool for bridge management system in operation and maintenance phase. The paper provides a detailed description for each use of BrIM model in design, construction, and operation and maintenance phases of bridges. It is proven that BrIM is an effective tool for bridge management systems throughout their life phases.

• 한국BIM학회 논문집
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• 제2권2호
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• pp.37-45
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• 2012

부재를 표준화하여 설계 및 제작 생산성을 높이고 기계화 시공을 가능하게 하는 모듈러 교량이 건설 산업에서 중요하게 대두되고 있다. 반복성이 높고 설계, 제작 시공 과정에서의 정보의 원활한 전달이 필요하기 때문에 BIM(Building Information Modeling) 기술에 기반한 변수 모델링 정의를 제시하였다. 모듈러 교량이 갖는 변수 범위를 고려하여 고정변수, 변동변수, 연관변수로 구분하여 정의하고 이를 설계, 해석, 제작에 활용할 수 있도록 하였다. 구조시스템 개발과정의 지식을 정보화하여 3차원 모델의 정확성과 활용성을 높였다.

• 한국디지털건축인테리어학회논문집
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• 제10권3호
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• pp.11-18
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• 2010

Cost estimation through fast and correct quantity take offs are crucial in the process of construction project. The existing methods for cost estimation are mainly based on 2D-based drawings and the estimation result tends to be different according to the estimator's experience, the quality and quantity of used information and estimation time. To solve these problems, the domestic construction industry have recently tried to use the data extracted from 3D data modeling based on BIM(Building Information Modeling) in order to achieve more accurate and objective cost estimation. However it tends to increase dramatically the quantity of information that can be used in cost estimation by estimators. Therefore in order to achieve quality information data from 3D data modeling, the characteristics of the project should be reflected on the 3D model and it is most important to extract information only for cost estimation from the whole 3D model fast and accurately. Thus this study aims to propose the 3D modeling method through Data Normalization which maximizes the usability of 3D Data modeling in cost estimation process.

• 한국지능시스템학회논문지
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• 제19권2호
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• pp.197-205
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• 2009

미래 디지털 환경에서 에너지 관리 시스템은 예기치 못한 정전이나 과부하 같은 응급 상황 이벤트들이 발생하면 이를 실시간으로 대처할 수 있어야 하고, 원격 검침과 같은 소비자 서비스 이벤트들도 신속하게 제공되어야 한다. 따라서 다양한 에너지 이벤트 정보들을 실시 간으로 전달할 수 있는 단순하면서 장치 독립적인 정보 교환 모델이 필요하다. 이에 본 논문에서는 XML을 기반으로 객체 지향 모델링을 사용하여 장치와 이벤트 모델링을 분리한 esXML을 개발하였다. 실험 결과 독립적이고 효율적으로 정보 교환을 할 수 있었다.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2002년도 춘계학술대회 논문집
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• pp.3-8
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• 2002

This paper introduces the basic concept of computational modeling of perception processes for multimedia data. Such processes are modeled as hierarchical inter- and intra- relationships amongst information in physical, physiological, psychological and cognitive layers in perception. Based on our framework, this paper gives the algorithms for content-based retrieval for multimedia database systems.