• Nuclear Engineering and Technology
• /
• 제55권11호
• /
• pp.4228-4237
• /
• 2023

The Improved Deterministic Truncation of Monte Carlo (iDTMC) is a powerful acceleration and variance reduction scheme in the Monte Carlo analysis. The concept of the iDTMC method and correlated sampling-based real variance estimation are briefly introduced. Moreover, the application of the iterative scheme to the correlated sampling is discussed. The iDTMC method is utilized in a 3-dimensional small modular reactor (SMR) model problem. The real variances of burnup-dependent criticality and power distribution are evaluated and compared with the ones obtained from 30 independent iDTMC calculations. The impact of the inactive cycles on the correlated sampling is also evaluated to investigate the consistency of the correlated sample scheme. In addition, numerical performances and sensitivity analysis on the real variance estimation are performed in view of the figure of merit of the iDTMC method. The numerical results show that the correlated sampling accurately estimates the real variances with high computational efficiencies.

• 한국통신학회논문지
• /
• 제33권1C호
• /
• pp.53-61
• /
• 2008

본 논문에서는 2차원 동영상에서 다시점 동영상을 생성하는 방법을 제안한다. 다시점 동영상의 생성을 위해 공간적으로 색상 정보, 시간적으로 움직임 정보를 이용한다. 색상 정보는 객체의 정확한 외곽을 추출하기 위하여 사용된다. 색상의 동질영역을 구분하기 위하여 휘도와 색차 정보를 이용하며, 움직임 정보를 구하기 위하여 정합창을 이용한 화소기반의 움직임 예측을 수행한다. 다음 단계는 색상 정보와 움직임 예측을 통해 얻어진 결과를 결합한다. 움직임 예측을 통해 얻은 움직임의 세기 값을 색상정보를 이용해 얻은 각 영역에 할당하고 이를 깊이 값으로 변환한다. 2차원의 입력 영상과 변환되어진 깊이 정보를 통해 회전변환 과정을 거쳐 최종적으로 다시점 동영상을 생성한다. 기존의 2차원 동영상의 3차원 동영상 변환과의 주관적 평가를 통해 효과적으로 다시점 영상을 생성함을 확인 할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제7권11호
• /
• pp.2720-2736
• /
• 2013

Multi-view face detection has become an active area for research in the last few years. In this paper, a novel multi-view human face detection algorithm based on improved real Adaboost is presented. Real Adaboost algorithm is improved by weighted combination of weak classifiers and the approximately best combination coefficients are obtained. After that, we proved that the function of sample weight adjusting method and weak classifier training method is to guarantee the independence of weak classifiers. A coarse-to-fine hierarchical face detector combining the high efficiency of Haar feature with pose estimation phase based on our real Adaboost algorithm is proposed. This algorithm reduces training time cost greatly compared with classical real Adaboost algorithm. In addition, it speeds up strong classifier converging and reduces the number of weak classifiers. For frontal face detection, the experiments on MIT+CMU frontal face test set result a 96.4% correct rate with 528 false alarms; for multi-view face in real time test set result a 94.7 % correct rate. The experimental results verified the effectiveness of the proposed approach.

• 대한조선학회논문집
• /
• 제40권5호
• /
• pp.43-52
• /
• 2003

Two methods which estimate manoeuvring derivatives in the model of hydrodynamic force and moment acting on a manoeuvring ship using sea trial data were compared. One is the widely used parameter estimation method by using the Extended Kalman Filter (EKF), which estimates state variables of linearized state space model at every instant after dealing with the coefficients as the augmented state variables. The other one is the Estimation-Before-Modeling (EBM) technique, so called the two-step method. In the first step, hydrodynamic force of which dynamic model is assumed the third-order Gauss-Markov process is estimated along with motion variables by the EKF and the modified Bryson-Frazier smoother. Then, in the next step, manoeuvring derivatives are identified through the regression analysis. If the exact structure of hydrodynamic force could be known, which was an ideal case, the EKF method would be regarded as being more superior compared to the EBM technique. However the EBM technique was more robust than the EKF method from a realistic point of view where the assumed model structure was slightly different from the real one.

• Journal of Advanced Marine Engineering and Technology
• /
• 제36권4호
• /
• pp.512-519
• /
• 2012

본 논문은 원형 링 패턴의 인식에 기반한 물체의 3차원 위치/자세 추정 시스템을 제안한다. 단일 비전 기반의 자세추정 문제를 다루기 위하여, 본 논문은 물체인식 과정의 단순화를 위한 원형 링 패턴의 설계방법을 기술한다. 또한, 본 논문은 2차원 투영공간에서 원형 링 패턴이 가지는 기하학적 변환관계를 적극 활용한 실내용 위치/자세 추정 절차를 상세히 설명한다. 제안된 방법은 쿼드로터형 비행체의 3차원 위치/자세 추정에 적용되며 정확도 및 정밀도 분석을 통해 평가된다.

• IEIE Transactions on Smart Processing and Computing
• /
• 제2권5호
• /
• pp.317-321
• /
• 2013

This paper proposes a detection algorithm for view reversal in a stereoscopic video using a disparity map and motion vector field. We obtain the disparity map of a stereo image was obtained using a specific stereo matching algorithm and classify the image into the foreground and background. Next, the motion vector field of the image on a block basis was produced using a full search algorithm. Finally, the stereo image was considered to be reversed when the foreground moved toward the background and the covered region was in the foreground. The proposed algorithm achieved a good detection rate when the background was covered sufficiently by its moving foreground.

• 로봇학회논문지
• /
• 제17권3호
• /
• pp.353-358
• /
• 2022

Due to the limited field of view of the pinhole camera, there is a lack of stability and accuracy in camera pose estimation applications such as visual SLAM. Nowadays, multiple-camera setups and large field of cameras are used to solve such issues. However, a multiple-camera system increases the computation complexity of the algorithm. Therefore, in multiple camera-assisted visual simultaneous localization and mapping (vSLAM) the multi-view tracking algorithm is proposed that can be used to balance the budget of the features in tracking and local mapping. The proposed algorithm is based on PanoSLAM architecture with a panoramic camera model. To avoid the scale issue 3D LiDAR is fused with omnidirectional camera setup. The depth is directly estimated from 3D LiDAR and the remaining features are triangulated from pose information. To validate the method, we collected a dataset from the outdoor environment and performed extensive experiments. The accuracy was measured by the absolute trajectory error which shows comparable robustness in various environments.

• International journal of advanced smart convergence
• /
• 제11권1호
• /
• pp.1-10
• /
• 2022

Single-view reconstruction (SVR) is a fundamental method in computer vision. Often used for reconstructing human-made environments, the Manhattan world assumption presumes that planes in the real world exist in mutually orthogonal directions. Accordingly, this paper addresses an automatic SVR algorithm for Manhattan worlds. A method for estimating the directions of planes using graph-cut optimization is proposed. After segmenting an image from extracted line segments, the data cost function and smoothness cost function for graph-cut optimization are defined by considering the directions of the line segments and neighborhood segments. Furthermore, segments with the same depths are grouped during a depth-estimation step using a minimum spanning tree algorithm with the proposed weights. Experimental results demonstrate that, unlike previous methods, the proposed method can identify complex Manhattan structures of indoor and outdoor scenes and provide the exact boundaries and intersections of planes.

• 한국전자거래학회지
• /
• 제15권1호
• /
• pp.139-155
• /
• 2010

본 논문의 목적은 소프트웨어 사업대가기준의 중장기 발전 방향을 도출하고 소프트웨어 사업대가기준의 프레임워크를 제시하는 것이다. 본 논문에서는 첫째, 소프트웨어 생명주기상의 모든 단계와 현재의 소프트웨어 사업대가기준과 모형들이 검토되고 분석되어졌다. 둘째, 소프트웨어 사업대가기준의 중장기적 발전 대안으로 단가와 지침을 분리하여 운영하고, 시장자율기능을 확대하는 방안을 도출하였다. 그리고 소프트웨어 사업대가기준의 중장기 발전대안의 선결과제로 비용 리포지토리의 구축, 소프트웨어 사업대가 지침화, 다양한 사업대가기준 모형화 및 인증제 도입, 사업대가 전문가제도 도입이 제시되었다. 마지막으로 소프트웨어 사업대가기준의 중장기 발전대안의 단계별 이행계획이 제시되었다.

• 한국CDE학회논문집
• /
• 제12권2호
• /
• pp.137-145
• /
• 2007

This paper concerns about residential environment analysis program implementation for design and analysis on public housing complexes such that view and daylight analysis processes are automated and integrated into existing design routine to achieve better design efficiency. Considering the architectural design trends this paper chooses ArchiCAD as a platform for a CAD system, which contains the concepts such as integrated object-oriented CAD, virtual building and BIM. Residential environment analysis system consists of three components. The first component is the 3D modeling part defining 3D form information for external geographic contour models, site models and interior/exterior of apartment buildings. The second is the parametric library part handling the design parameters for view and daylight analysis. The last is the user interface for the input/output and integration of data for the environment analysis. Daylight analysis shows rendered images as well as results of daylight reports and grades per time and performs the calculations for floor shadow. It separates the site-only analysis from the analysis of site and exterior environmental parameters. View analysis considers horizontal and vertical view angles to produce view image from each unit and uses the bitmap analysis method to determine opening ratio, scenery ratio and void ratio. We could expect better performance and precision from this residential environment analysis system than the existing 2D drawing based view and daylight analysis methods and overcome the existing one-way flow of design information from 3D form to analysis reports so that site design modifications are automatically reflected on analysis results. Each part is developed in a module so that further integration and extension into other related estimation and construction management systems are made possible.