• 방송공학회논문지
• /
• 제16권1호
• /
• pp.44-53
• /
• 2011

본 논문에서는 depth layer partition을 이용한 2D 동영상의 자동 3D 변환 기법을 제안한다. 제안하는 기법에서는 먼저 2D 동영상의 장면 전환점을 검출하여 각각의 프레임 그룹을 설정하여 움직임 연산 과정에서의 오류 확산을 방지하여 깊이맵(depth map) 생성과 정에서 오차를 줄여준다. 깊이정보는 두 가지 방법으로 생성되는데 하나는 영역 분할과 움직임 정보를 이용하여 깊이맵을 추출하는 것이고 다른 하나는 에지 방향성 히스토그램(edge directional histogram)을 이용하는 방법이다. 제안하는 기법에서는 객체와 배경을 분리하는 depth layer partition 과정을 수행한 후 생성된 두 개의 깊이맵을 원 영상에 최적이 되도록 병합하게 된다. 제안된 기법으로 신뢰도 높은 깊이맵과 결과 영상을 생성할 수 있다는 것을 다양한 실험 결과를 통해 알 수 있다.

• 정보처리학회논문지D
• /
• 제9D권4호
• /
• pp.571-578
• /
• 2002

시간 데이터베이스에서 데이터의 이력 관리를 목적으로 확장된 시간 차원은 조인 연산에 대한 복잡도와 연산 비용의 증가를 초래한다. 이와 같은 문제를 해결하기 위해 조인 연산의 대상이 되는 시간 범위를 일정 정도의 시간 간격으로 분할한 후 분할된 세그먼트 단위의 시간 데이터들을 조인하는 방법이 제안되었다. 하지만 기존의 방법들은 분할점 근방에서 분할에 적용된 시간 단위 등의 문제로 인해 발생하는 시간 경계의 모호성 문제를 해결할 수 없다. 이러한 문제를 해결하기 위해 이 논문에서는 분할선 근방의 경계가 불확실한 시간 간격을 고려한 분할 방법으로 퍼지 이론의 가능성 분포를 도입한 퍼지 최소 간격 분할(Fuzzy Minimum Interval Partition : FMIP)기법을 제안하고 이를 기존 기법들과 비교 평가함으로써 FMIP의 타당성을 검증한다.

• 태양에너지
• /
• 제2권1호
• /
• pp.1-8
• /
• 1982

A theoretical study by numerical method has been performed on the natural convection of an air contained in enclosures. The enclosures have rectangular cross section with one vertical wall heated and the other cooled, and with two horizontal partition plates of finite thermal conductivity. Steady two-dimensional flow was assumed. The computation was executed by means of the Implicit Alternating Direction (I.A.D) finite-difference method. Two partition plates of Aluminium whose thickness were 0.05mm was employed in computation. Isothemals, streamlines, local Nusselt numbers and mean Nusselt numbers were obtained for various Grashof numbers and aspect ratio and these results were compared with those in the case of the enclosure with two horizontal insulated plates. From the present results, the heat transfer in the case of partition plates was greater than that in the case of insulation. This study suggests a method to measure the overall heat-transfer of coefficient in double walls which supported by partition plates for insulative construction.

• 설비공학논문집
• /
• 제5권4호
• /
• pp.285-294
• /
• 1993

An oscillatory motion of natural convection in a two-dimensional square enclosure fitted with a horizontal partition is investigated numerically. The enclosure was composed of the lower hot and the upper cold horizontal walls and the adiabatic vertical walls, and a partition was positioned perpendicularly at the mid-height of one vertical insulated wall. The governing equations are solved by using the finite element method with Galerkin method. The computations were carried out with the variations of the partition length and Rayleigh number based on the temperature difference between two horizontal walls and the enclosure height with water(Pr=4.95). As the results, an oscillatory motion of natural convection has perfectly shown the periodicity with the decrease of Rayleigh number, and the stability was reduced to a chaotic state with the increase of Rayleigh number. The period of oscillation gets shorten with the decrease of the partition length and the increase of Rayleigh number. The frequency of oscillation obtained by the variations of stream function is more similar to the experimental results than that of the average Nusselt number. The stability of oscillation grows worse with the increase of Rayleigh number. The transition Rayleigh number for the chaos is gradually decreased with the increase of the partition length.

• 설비공학논문집
• /
• 제6권3호
• /
• pp.302-314
• /
• 1994

The effects of the inclination of enclosure and partition on natural convective flow and heat transfer were investigated numerically. The enclosure was composed of the lower hot and the upper cold horizontal walls and the adiabatic vertical walls, and a partition was positioned perpendicularly at the mid-height of one vertical insulated wall. The governing equations are solved by using the finite element method with Galerkin method. The computations were performed with the variations of the partition length and Rayleigh number based on the temperature difference between two horizontal walls and the enclosure height with water(Pr=4.95). The effects of the inclination angle of enclosure and partition on the heat transfer within an enclosure were also studied. As the results, the increase of the inclination angle of enclosure rapidly raised the heat transfer rate, while the inclination angle for the maximum Nusselt number was retarded with the increase of the partition length and the decrease of the heat transfer rate became larger in proportion to the increase of the partition length. The Nusselt number obtained by the inclination of partition was smaller than that of the inclination of enclosure. However, the difference of the heat transfer rates was considerably decreased at the longer partition lengths and the trends for the variation of the average Nusselt number were more similar with that of the inclination of enclosure. The upward oriented partition increases the convective heat transfer distinctly in contrast to that of the inclination of enclosure as the partition length increases.

• Computers and Concrete
• /
• 제4권1호
• /
• pp.67-82
• /
• 2007

The discrete crack-concept is applied to study the 3D propagation of tensile-dominated failure in plain concrete. To this end the Partition of Unity Finite Element Method (PUFEM) is utilized and the strong discontinuity approach is followed. A consistent linearized implementation of the PUFEM is combined with a predictor-corrector algorithm to track the crack path, which leads to a robust numerical description of concrete cracking. The proposed concept is applied to study concrete failure during the PCT3D test and the predicted numerical results are compared to experimental data. The proposed numerical concept provides a clear interface for constitutive models and allows an investigation of their impact on concrete cracking under 3D conditions, which is of significant scientific interests to interpret results from 3D experiments.

• Nuclear Engineering and Technology
• /
• 제31권6호
• /
• pp.572-585
• /
• 1999

The characteristics of two-phase flow instability in a vertical boiling channel connecting with an unheated riser are investigated through the linear stability analysis model. Various two-phase flow models, including thermal non-equilibrium effects, are taken into account for establishing a physical model in the time domain. A classical approach to the frequency response method is adopted for the stability analysis by employing the D-partition method. The adequacy of the linear model is verified by evaluating experimental data at high quality conditions. It reveals that the flow-pattern-dependent drift velocity model enhances the prediction accuracy while the homogeneous equilibrium model shows the most conservative predictions. The characteristics of density wave oscillations under low-power and low-quality conditions are investigated by devising a simple model which accounts for the gravitational and frictional pressure losses along the channel. The necessary conditions for the occurrences of type-I instability and flow excursion are deduced from the one-dimensional D-partition analysis. The parametric effects of some design variables on low quality oscillations are also investigated.

• Journal of the Korean Statistical Society
• /
• 제35권1호
• /
• pp.49-61
• /
• 2006

Wu et al. (1992) constructed some general classes of tight asymmetric orthogonal arrays of strength 2 using the method of grouping. Rains et al. (2002) obtained asymmetric orthogonal arrays of strength 2 using the concept of mixed spread in finite projective geometry. In this paper, we obtain some new tight asymmetric orthogonal arrays of strength 2 using the concept of mixed partition in finite projective geometry.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집E
• /
• pp.708-713
• /
• 2001

The paper presented some results of a experimental study of natural convection in partitioned 2D square enclosure. The square enclosure consist of two adiabatic vertical walls and the upper cold and the lower hot walls. A partition is positioned perpendicularly at the center of left vertical insulated wall The PIV mesaurements were performed with the variations of the partition length and inclination of enclosure. The working fluid is water with a Prandtl number of 6.996 at $20^{\circ}C$ temperature. A captured images were calculated by using a Cross-Correlation(Multi-frame/Single-exposure) method.

• 대한기계학회논문집B
• /
• 제26권2호
• /
• pp.310-317
• /
• 2002

In the present study, an experimental study of natural convection in a partitioned 2D square enclosure has been carried out. The square enclosure consist of two adiabatic vertical walls and the upper cold and the lower hot walls. A partition is positioned perpendicularly at the center of the left vortical insulated wall. The PIV measurements were performed with the variations of Rayleigh number, partition length and inclination of the enclosure. The working fluid is water with Prandtl number of 6.996 at 20$\^{C}$. The captured images were analyzed by using a cross-correlation (two-frame/single-exposure) PIV method.