• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.587-590
• /
• 2005

Reactive plans for a box-pushing task of a mobile robot are automatically built up, where sequential action plans are found in a configuration space by A* algorithm for various initial configurations. Then, conjunction of conditions to associate with a same behavior are found by a back tracking algorithm. And corresponding reactive plans are generated. Finally, a clustering technique is applied to identify which reactive plan should be applied for a given perceptual condition. Several simulation results are shown to justify our proposed approach.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.3
• /
• pp.110-119
• /
• 1998

In this paper we discuss an algorithm to discriminate a garget under track against multiple acoustic counter-measure (ACM) sources, based on sequential testings of multiple hypotheses. The ACM sources are separated from the target under track and generate, while drifting, measurements with false range and Doppler information. The purpose of the ACM is to mislead the target tracking and to help the true target evade a pursuer. The proposed algorithm uses as a test statistic a function of the innovation sequences from extended Kalman filters to estimate the target dynamics and the drifting positions of the ACM sources. results of numerical experimenats are presented to show a performance profile of the proposed algorithm.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.9 no.1
• /
• pp.25-32
• /
• 2014

In this paper, we proposed a partial-way set associative cache memory with an effective memory access time and low energy consumption. In the proposed set-associative cache memory, it is allowed to access only a 2-ways among 4-way at a time. Choosing ways to be accessed is made dynamically via the least significant two bits of the tag. The chosen 2 ways are sequentially accessed by the way selection bits that indicate the most recently referred way. Therefore, each entry in the way has an additional bit, that is, the way selection bit. In addition, instead of the 4-way LRU or FIFO algorithm, we can utilize a simple 2-way replacement policy. Simulation results show that the energy*delay product can be reduced by about 78%, 14%, 39%, and 15% compared with a 4-way set associative cache, a sequential-way cache, a way-tracking cache, and a way cache respectively.

• Journal of Information Display
• /
• v.3 no.2
• /
• pp.19-25
• /
• 2002

In this paper, a new target extraction algorithm is proposed, in which the coordinates of target are obtained adaptively by using the difference image information and the optical BPEJTC(binary phase extraction joint transform correlator) with which the target object can be segmented from the input image and background noises are removed in the stereo vision system. First, the proposed algorithm extracts the target object by removing the background noises through the difference image information of the sequential left images and then controlls the pan/tilt and convergence angle of the stereo camera by using the coordinates of the target position obtained from the optical BPEJTC between the extracted target image and the input image. From some experimental results, it is found that the proposed algorithm can extract the target object from the input image with background noises and then, effectively track the target object in real time. Finally, a possibility of implementation of the adaptive stereo object tracking system by using the proposed algorithm is also suggested.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.10 s.253
• /
• pp.1235-1241
• /
• 2006

A new hydrocode which is still under development using Lagrangian, Eulerian and arbitrary Lagrangian-Eulerian operators, has been described. The three operators are implemented into a single framework by incorporating the sequential three stages of Lagrangian, remesh and remap stages. Several numerical schemes used for each operator are discussed briefly in this paper. In order to evaluate the characteristics of each operator, the Taylor Impact Test has been simulated using each operator and the results are compared. Currently the code is 1st order accuracy in the material interface tracking algorithm and can not handle multimaterial in the mixed cell. The areas of possible enhancement of the code are also discussed.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2014.01a
• /
• pp.149-151
• /
• 2014

주의(attention)를 어떻게 할당하는가는 정신물리학뿐만 아니라, 컴퓨터 시각과정을 모델링하는데 중요한 주제 중 하나이다. 기존 연구는 saliency와 같은 활성화 값에 의해서 주의탐사 순위가 결정된다. 본 논문에서는 주의탐사과정을 병렬처리를 통한 활성화 값 추출과정과 순차적 처리를 통한 공간적 전략과정으로 구분하였다. 단서패러다임에 기초한 계산모형을 이용하여, 실제 인간의 수행결과를 AUC와 Levenshtein 척도를 이용하여 비교하였다. Fixation point 비교에서는 인간과 활성화를 기반으로 한 계산모형의 수행은 높은 상관성을 가지고 있었다. 주의궤적 혹은 scanpath 분석에서는 활성화기반 전략보다는 공간적 전략 모형이 더 높은 유사성을 보였다. 이는 주의탐사과정이 병렬처리과정을 통해 얻어진 saliency에 의해서만 결정되는 것이 아니라, 목표물간의 근접성 등의 공간적 전략을 통해 순차적 (sequential) 경로가 생성됨을 의미한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.653-656
• /
• 2002

본 논문에서는 연속된 영상 정보를 이용하여 물체를 추적하는 시스템에 대하여 기술한다. 물체를 추적하는 시스템은 물체를 구별하는 단계에서 자동으로 물체를 추적하는 단계로 구성된다. 물체를 구별 하기 위해서는 영상에서 사용자가 원하는 물체를 추출해야 한다. 이를 위해서 여러 가지 전처리 과정을 거쳐서 물체를 추출하고, 물체에 대한 정보를 추출한다. 추출된 정보와 미리 입력된 물체에 대한 정보와 비교하여 사용자가 원하는 물체인지를 구별한다. 사용자가 원하는 물체라고 판단이 될 경우 추적 시스템은 추적 알고리즘을 이용하여 물체를 추적한다. 이 시스템을 평가하기 위해서 본 논문은 conveyor belt에서 물체를 추적, 추적된 물체를 잡는 실험을 하였고 성공적인 결과를 보였다.

• Environmental Engineering Research
• /
• v.19 no.2
• /
• pp.165-174
• /
• 2014

A model combining multi-dimensional discretized population balance equations with a computational fluid dynamics simulation (CFD-DPBE model) was developed and applied to simulate turbulent flocculation and sedimentation processes in sediment retention basins. Computation fluid dynamics and the discretized population balance equations were solved to generate steady state flow field data and simulate flocculation and sedimentation processes in a sequential manner. Up-to-date numerical algorithms, such as operator splitting and LeVeque flux-corrected upwind schemes, were applied to cope with the computational demands caused by complexity and nonlinearity of the population balance equations and the instability caused by advection-dominated transport. In a modeling and simulation study with a two-dimensional simplified pond system, applicability of the CFD-DPBE model was demonstrated by tracking mass balances and floc size evolutions and by examining particle/floc size and solid concentration distributions. Thus, the CFD-DPBE model may be used as a valuable simulation tool for natural and engineered flocculation and sedimentation systems as well as for flocculant-aided sediment retention ponds.

• Journal of KIISE:Software and Applications
• /
• v.37 no.1
• /
• pp.29-38
• /
• 2010

We propose an interactive projection technique to display details of a large image in a high resolution and brightness by tracking a portable projector. A closed-loop based tracking method is presented to update the projected image while a user changes the position of the detail area by moving the portable projector. A marker is embedded in the large image to indicate the position to be occupied by the detail image projected by the portable projector. The marker is extracted in sequential images acquired by a camera attached to the portable projector. The marker position in the large display image is updated under a constraint that the center positions of marker and camera frame coincide in every camera frame. The image and projective transformation for warping are calculated using the marker position and shape in the camera frame. The marker's four corner points are determined by a four-step segmentation process which consists of camera image preprocessing based on HSI, edge extraction by Hough transformation, quadrangle test, and cross-ratio test. The interactive projection system implemented by the proposed method performs at about 24fps. In the user study, the overall feedback about the system usability was very high.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.1
• /
• pp.128-135
• /
• 2009

Techniques for tracking the same region of physical space with the temporal sequences of images by matching the contours of constant phase show robust and stable performance in relative to the tracking techniques using or assuming the constant intensity. Using this property, we describe an algorithm for obtaining the robust motion parameters caused by the global camera motion. First, we obtain the optical flow based on the phase of spacially filtered sequential images on the region in a direction orthogonal to orientation of each component of gabor filter bank. And then, we apply the least squares method to the optical flow to determine the affine motion parameters. We demonstrate hat proposed method can be applied to the vision based pointing device which estimate its motion using the image including the display device which cause lighting condition varieties and noise.