![]() Edge-based features from omnidirectional images for robot localizationVlassis, Nikos ; ; et alin Proc. IEEE Int. Conf. on Robotics and Automation (2001) Detailed reference viewed: 136 (0 UL) Fast score function estimation with application in ICAVlassis, Nikos ![]() in Proc. Int. Conf. on Artificial Neural Networks (2001) Detailed reference viewed: 127 (0 UL) Supervised linear feature extraction for mobile robot localizationVlassis, Nikos ; ; in Proc. IEEE Int. Conf. on Robotics and Automation (2000) We are seeking linear projections of supervised high-dimensional robot observations and an appropriate environment model that optimize the robot localization task. We show that an appropriate risk ... [more ▼] We are seeking linear projections of supervised high-dimensional robot observations and an appropriate environment model that optimize the robot localization task. We show that an appropriate risk function to minimize is the conditional entropy of the robot positions given the projected observations. We propose a method of iterative optimization through a probabilistic model based on kernel smoothing. To obtain good starting optimization solutions we use canonical correlation analysis. We apply our method on a real experiment involving a mobile robot equipped with an omnidirectional camera in an office setup. [less ▲] Detailed reference viewed: 167 (0 UL)![]() Mixture density estimation based on Maximum Likelihood and test statisticsVlassis, Nikos ; ; in Neural Processing Letters (1999), 9(1), 63-76 Detailed reference viewed: 152 (0 UL)![]() An information-theoretic localization criterion for robot map buildingVlassis, Nikos ; ; in Proc. ACAI'99, Int. Conf. on Machine Learning and Applications (1999) Detailed reference viewed: 136 (0 UL) Robot environment modeling via principal component regressionVlassis, Nikos ; in Proc. of Intelligent Robots and Systems, International Conference on (1999) A key issue in mobile robot applications involves building a map of the environment to be used by the robot for localization and path planning. We propose a framework for robot map building which is based ... [more ▼] A key issue in mobile robot applications involves building a map of the environment to be used by the robot for localization and path planning. We propose a framework for robot map building which is based on principal component regression, a statistical method for extracting low-dimensional dependencies between a set of input and target values. A supervised set of robot positions (inputs) and associated high-dimensional sensor measurements (targets) are assumed. A set of globally uncorrelated features of the original sensor measurements are obtained by applying principal component analysis on the target set. A parametrized model of the conditional density function of the sensor features given the robot positions is built based on an unbiased estimation procedure that fits interpolants for both the mean and the variance of each feature independently. The simulation results show that the average Bayesian localization error is an increasing function of the principal component index. [less ▲] Detailed reference viewed: 167 (0 UL) Mixture Conditional Density Estimation with the EM AlgorithmVlassis, Nikos ; in Proc. 9th Int. Conf. on Artificial Neural Networks (1999) Detailed reference viewed: 202 (0 UL)![]() Appearance-Based Robot Localization; ; Vlassis, Nikos et alin Proc. IJCAI'99, 16th Int. Joint Conf. on Artificial Intelligence, ROB-2 Workshop (1999) Detailed reference viewed: 117 (0 UL)![]() A kurtosis-based dynamic approach to Gaussian mixture modelingVlassis, Nikos ; in IEEE Transactions on Systems, Man and Cybernetics. Part A, Systems and Humans (1999), 29(4), 393-399 We address the problem of probability density function estimation using a Gaussian mixture model updated with the expectation-maximization (EM) algorithm. To deal with the case of an unknown number of ... [more ▼] We address the problem of probability density function estimation using a Gaussian mixture model updated with the expectation-maximization (EM) algorithm. To deal with the case of an unknown number of mixing kernels, we define a new measure for Gaussian mixtures, called total kurtosis, which is based on the weighted sample kurtoses of the kernels. This measure provides an indication of how well the Gaussian mixture fits the data. Then we propose a new dynamic algorithm for Gaussian mixture density estimation which monitors the total kurtosis at each step of the Ehl algorithm in order to decide dynamically on the correct number of kernels and possibly escape from local maxima. We show the potential of our technique in approximating unknown densities through a series of examples with several density estimation problems. [less ▲] Detailed reference viewed: 254 (1 UL)![]() Dynamic Sensory Probabilistic Maps for Mobile Robot LocalizationVlassis, Nikos ; ; in Proc. IEEE/RSJ Int. Conf. on Intelligent Robots and Systems (1998) Detailed reference viewed: 164 (0 UL)![]() A Sensory Uncertainty Field Model for Unknown and Non-stationary Mobile Robot EnvironmentsVlassis, Nikos ; in Proc. IEEE Int. Conf. on Robotics and Automation (1998) Detailed reference viewed: 157 (0 UL)![]() The Probabilistic Growing Cell Structures AlgorithmVlassis, Nikos ; ; in Proc. Int. Conf. on Artificial Neural Networks (1997) Detailed reference viewed: 170 (0 UL)![]() Global Path Planning for Autonomous Qualitative NavigationVlassis, Nikos ; ; et alin Proc. 8th IEEE Int. Conf. on Tools with AI (1996) Detailed reference viewed: 206 (0 UL)![]() An Experiment for Truly Parallel Logic Programming; Vlassis, Nikos ; et alin Journal of Intelligent and Robotic Systems (1996), 16(2), 169-184 Detailed reference viewed: 196 (1 UL) |
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