• Title/Summary/Keyword: MAP algorithm

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Optimal algorithm of FOV for solder joint inspection using neural network (신경회로망을 이용한 납땜 검사 FOV의 최적화 알고리즘)

  • 오제휘;차영엽
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1549-1552
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    • 1997
  • In this paper, a optimal algorithm that can produce the FOV is proposed in terms of using the Kohonen's Self-Organizing Map(KSOM). A FOV, that stands for "Field Of View", means maximum area where a camera could be wholly seen and influences the total time of inspection of vision system. Therefore, we draw algorithm with a KSOM which aims to map an input space of N-dimensions into a one-or two-dimensional lattice of output layer neurons in order to optimize the number and location of FOV, instead of former sequentila method. Then, we show demonstratin through computer simulation using the real PCB data. PCB data.

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Robust Localization Algorithm for Mobile Robots in a Dynamic Environment with an Incomplete Map (동적 환경에서 불완전한 지도를 이용한 이동로봇의 강인한 위치인식 알고리즘의 개발)

  • Lee, Jung-Suk;Chung, Wan Kyun;Nam, Sang Yep
    • IEMEK Journal of Embedded Systems and Applications
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    • v.3 no.2
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    • pp.109-118
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    • 2008
  • We present a robust localization algorithm using particle filter for mobile robots in a dynamic environment. It is difficult to describe moving obstacles like people or other robots on the map and the environment is changed after mapping. A mobile robot cannot estimate its pose robustly with this incomplete map because sensor observations are corrupted by un-modeled obstacles. The proposed algorithms provide robustness in such a dynamic environment by suppressing the effect of corrupted sensor observations with a selective update or a sampling from non-corrupted window. A selective update method makes some particles keep track of the robot, not affected by the corrupted observation. In a sampling from non-corrupted window method, particles are always sampled from several particle sets which use only non-corrupted observation. The robustness of proposed algorithm is validated with experiments and simulations.

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Efficient Sweeping Algorithm for Multi-Security Mobile Robots (군집 이동형 사회안전 로봇을 위한 효율적인 수색 알고리즘 개발)

  • Shon, Woong-Hee;Han, Chang-Soo;Ji, Sang-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.9
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    • pp.1686-1691
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    • 2010
  • In this paper, we aim at providing a novel sweeping method for multi-security mobile robots. The sweeping problem of the multi-robots can be modeled as the stick pulling problem in which the swarm robots should sweep unknown terrains in order to remove sticks collaboratively. For the purpose, we define a certain map, what is called stick map. And we suggest how to make swarm robots build up and utilize the map in order to improve the productivity of collaborative removing sticks. Finally, the efficiency of our algorithm is verified with simulation experiments.

Disparity Refinement near the Object Boundaries for Virtual-View Quality Enhancement

  • Lee, Gyu-cheol;Yoo, Jisang
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.2189-2196
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    • 2015
  • Stereo matching algorithm is usually used to obtain a disparity map from a pair of images. However, the disparity map obtained by using stereo matching contains lots of noise and error regions. In this paper, we propose a virtual-view synthesis algorithm using disparity refinement in order to improve the quality of the synthesized image. First, the error region is detected by examining the consistency of the disparity maps. Then, motion information is acquired by applying optical flow to texture component of the image in order to improve the performance. Then, the occlusion region is found using optical flow on the texture component of the image in order to improve the performance of the optical flow. The refined disparity map is finally used for the synthesis of the virtual view image. The experimental results show that the proposed algorithm improves the quality of the generated virtual-view.

A New Calibration Algorithm of a Five-Hole Pressure Probe for Flow Velocity Measurement (유동속도계측을 위한 5공압력프로브의 새로운 교정 알고리듬)

  • Kim, J.K.;Oh, S.H.
    • Journal of Power System Engineering
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    • v.12 no.4
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    • pp.18-25
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    • 2008
  • This paper investigated the new calibration algorithm of a straight-type five-hole pressure probe necessary for calculating three-dimensional flow velocity components. The new data reduction method Includes a look-up, a geometry transformation such as the translation and reflection of nodes, and a binary search algorithm. This new calibration map was applied up to the application angle, ${\pm}55^{\circ}$ of a probe. As a result, this data reduction method showed a perfect performance without any kind of interpolation errors In calculating yaw and pitch angle from the calibration map.

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Hierarchical stereo matching using feature extraction of an image

  • Kim, Tae-June;Yoo, Ji-Sang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.99-102
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    • 2009
  • In this paper a hierarchical stereo matching algorithm based on feature extraction is proposed. The boundary (edge) as feature point in an image is first obtained by segmenting an image into red, green, blue and white regions. With the obtained boundary information, disparities are extracted by matching window on the image boundary, and the initial disparity map is generated when assigned the same disparity to neighbor pixels. The final disparity map is created with the initial disparity. The regions with the same initial disparity are classified into the regions with the same color and we search the disparity again in each region with the same color by changing block size and search range. The experiment results are evaluated on the Middlebury data set and it show that the proposed algorithm performed better than a phase based algorithm in the sense that only about 14% of the disparities for the entire image are inaccurate in the final disparity map. Furthermore, it was verified that the boundary of each region with the same disparity was clearly distinguished.

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Propagation Neural Networks for Real-time Recognition of Error Data (에라 정보의 실시간 인식을 위한 전파신경망)

  • Kim, Jong-Man;Hwang, Jong-Sun;Kim, Young-Min
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.46-51
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    • 2001
  • For Fast Real-time Recognition of Nonlinear Error Data, a new Neural Network algorithm which recognized the map in real time is proposed. The proposed neural network technique is the real time computation method through the inter-node diffusion, In the network, a node corresponds to a state in the quantized input space. Each node is composed of a processing unit and fixed weights from its neighbor nodes as well as its input terminal. The most reliable algorithm derived for real time recognition of map, is a dynamic programming based algorithm based on sequence matching techniques that would process the data as it arrives and could therefore provide continuously updated neighbor information estimates. Through several simulation experiments, real time reconstruction of the nonlinear map information is processed,

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Convergence of MAP-EM Algorithms with Nonquadratic Smoothing Priors

  • Lee, Soo-Jin
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.361-364
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    • 1997
  • Bayesian MAP-EM approaches have been quite useful or tomographic reconstruction in that they can stabilize the instability of well-known ML-EM approaches, and can incorporate a priori information on the underlying emission object. However, MAP reconstruction algorithms with expressive priors often suffer from the optimization problem when their objective unctions are nonquadratic. In our previous work [1], we showed that the use of deterministic annealing method greatly reduces computational burden or optimization and provides a good solution or nonquadratic objective unctions. Here, we further investigate the convergence of the deterministic annealing algorithm; our experimental results show that, while the solutions obtained by a simple quenching algorithm depend on the initial conditions, the estimates converged via deterministic annealing algorithm are consistent under various initial conditions.

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Bio-inspired robot swarm control algorithm for dynamic environment monitoring

  • Kim, Kyukwang;Kim, Hyeongkeun;Myung, Hyun
    • Advances in robotics research
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    • v.2 no.1
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    • pp.1-11
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    • 2018
  • To monitor the environment and determine the source of a pollutant gradient using a multiple robot swarm, we propose a hybrid algorithm that combines two bio-inspired algorithms mimicking chemotaxis and pheromones of bacteria. The algorithm is implemented in virtual robot agents in a simulator to evaluate their feasibility and efficiency in gradient maps with different sizes. Simulation results show that the chemotaxis controller guided robot agents to the locations with higher pollutant concentrations, while the pheromone marked in a virtual field increased the efficiency of the search by reducing the visiting redundancy. The number of steps required to reach the target point did not increase proportionally as the map size increased, but were less than those in the linear whole-map search method. Furthermore, the robot agents could function with simple sensor composition, minimum information about the map, and low calculation capacity.

A Study of the Use of step by preprocessing and Graph Cut for the exact depth map (깊이맵 향상을 위한 전처리 과정과 그래프 컷에 관한 연구)

  • Kim, Young-Seop;Song, Eung-Yeol
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.3
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    • pp.99-103
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    • 2011
  • The stereoscopic vision system is the algorithm to obtain the depth of target object of stereo vision image. This paper presents an efficient disparity matching method using blue edge filter and graph cut algorithm. We do recommend the use of the simple sobel edge operator. The application of B band sobel edge operator over image demonstrates result with somewhat noisy (distinct border). The basic technique is to construct a specialized graph for the energy function to be minimized such that the minimum cut on the graph also minimizes the energy (either globally or locally). This method has the advantage of saving a lot of data. We propose a preprocessing effective stereo matching method based on sobel algorithm which uses blue edge information and the graph cut, we could obtain effective depth map.