• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.3
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• pp.20-29
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• 2008

In this paper, we propose a do-interlacing algorithm using integral projection-based motion estimation considering Region Of Interest(ROI). The proposed motion estimation method finds the motion of the given ROI accurately with low computational cost. In order to incorporate the motion estimation in do-interlacing, an entire image is first segmented into multiple ROIs according to the temporally predicted block-wise motion types and spatial positions. Then, motion vectors of respective ROIs are obtained by the integral projection method. In this paper, totally five ROIs, one for the global motion and four for the local motions, are made, and therefore, five motion vectors are produced for each field. By using the estimated motion vectors, motion compensation is performed for increasing the vortical resolution of the converted frames. Finally, do-interlaced frames are obtained by effectively combining the results of motion compensation and stable intra-field do-interlacing according to the reliability of motion compensation. Experimental results show that the proposed algorithm provides better image quality than existing algorithms in both subjective and objective measures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.12
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• pp.3315-3337
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• 2012

Crowded scenes analysis is a challenging topic in computer vision field. How to detect diverse motion patterns in crowded scenarios from videos is the critical yet hard part of this problem. In this paper, we propose a novel approach to mining motion patterns by utilizing motion information during both long-term period and short interval simultaneously. To capture long-term motions effectively, we introduce Motion History Image (MHI) representation to access to the global perspective about the crowd motion. The combination of MHI and optical flow, which is used to get instant motion information, gives rise to discriminative spatial-temporal motion features. Benefitting from the robustness and efficiency of the novel motion representation, the following motion pattern mining is implemented in a completely unsupervised way. The motion vectors are clustered hierarchically through automatic hierarchical clustering algorithm building on the basis of graphic model. This method overcomes the instability of optical flow in dealing with time continuity in crowded scenes. The results of clustering reveal the situations of motion pattern distribution in current crowded videos. To validate the performance of the proposed approach, we conduct experimental evaluations on some challenging videos including vehicles and pedestrians. The reliable detection results demonstrate the effectiveness of our approach.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.293-298
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• 1993

In this paper, methods for computing the time-optimal motion of a robotic manipulator are presented that considers the nonlinear manipulator dynamics, actuator constraints, joint limits, and obstacles. The optimization problem can be reduced to a search for the time-optimal path in the n-dimensional position space. These paths are further optimized with a local path optimization to yield a global optimal solution. Time-optimal motion of a robot with an articulated arm is presented as an example.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.141-144
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• 2002

This paper describes a new feature based tracking system that can track moving objects with a pan-tilt camera. We extract corner features of the scene and tracks the features using filtering, The global motion energy caused by camera movement is eliminated by finding the maximal matching position between consecutive frames using Pyramidal template matching. The region of moving object is segmented by clustering the motion trajectories and command the pan-tilt controller to follow the object such that the object will always lie at the center of the camera. The proposed system has demonstrated good performance for several video sequences.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1373-1379
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• 2006

Moving object extraction is one of key research topics for various video services. In this study, a new moving object extraction algorithm is introduced to extract objects using block motion vectors in video data. To do this, 1) a maximum a posteriori probability and Gibbs random field are used to obtain real block motion vectors,2) a 2-D histogram technique is used to determine a global motion, 3) additionally, a block segmentation is fellowed. In the computer simulation results, the proposed technique shows a good performance.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.996-1003
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• 1990

We present algebraic algorithms for collision-avoidance robot motion planning problems with planar geometric models. By decomposing the collision-free space into horizontal vertex visibility cells and connecting these cells into a connectivity graph, we represent the global topological structure of collision-free space. Using the C-space obstacle boundaries and this connectivity graph we generate exact (non-heuristic) compliant and gross motion paths of planar curved objects moving with a fixed orientation amidst similar obstacles. The gross motion planning algorithm is further extended (though using approximations) to the case of objects moving with both translational and rotational degrees of freedom by taking slices of the overall orientations into finite segments.

• Journal of Ship and Ocean Technology
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• v.4 no.3
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• pp.21-32
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• 2000

In the present paper, the sloshing flow in the liquid holds of a large tanker is simulated using a numerical method. In the fluid domain, the three-dimensional Navier-Stokes equation with free surface is solved using a finite difference method, and the realistic shapes of multi holds are modeled including the internal members. The time-history of the tank motion is obtained using a time-domain program for ship motion. In order to computer the impulsive pressures on internal structures, a concept of buffer zone is adopted near the tank ceiling during impact occurrence. This study demonstrates that the global fluid motion in the multi liquid holds of ships and FPSO's can be simulated using the numerical method and the corresponding local pressure can be predicted with reasonable accuracy.

• Journal of Korea Multimedia Society
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• v.22 no.1
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• pp.110-116
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• 2019

Virtual reality (VR) sickness can have an influential effect on the viewing quality of VR 3D contents. Particularly, watching the 3D contents on a head-mounted display (HMD) could cause some severe level of visual discomfort. Despite the importance of assessing the VR sickness, most of the recent studies have focused on unveiling the reason of inducing VR sickness. In this paper, we subjectively measure the level of VR sickness induced in the viewing of omnidirectional 3D graphics contents in HMD environment. Apart from that, we propose an objective assessment model that estimates the level of induced VR sickness by calculating the difference between head movement velocity and global camera motion velocity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.11
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• pp.2147-2151
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• 2011

In this paper, we propose the formation control algorithm for swarm robots. The proposed algorithm uses the artificial potential field(APF) to plan the global path of swarm robots and to control the formation movement. The navigation function generates a global APF for a leader robot to reach a given destination and an avoidance function generates a local APF for follow robots to avoid obstacles. Finally, some simulations show the validity of the proposed method.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.75-80
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• 2008

This paper proposes a method to detect scene change using global decision tree that extract boundary cut that have width of big change that happen by camera brake from difference value of frames. First, calculate frame difference value through regional X2-histogram and normalization, next, calculate distance between difference value using normalization. Shot boundary detection is performed by compare global threshold distance with distance value for two adjacent frames that calculating global threshold distance based on distance between calculated difference value. Global decision tree proposed this paper can detect easily sudden scene change such as motion from object or camera and flashlight.