One of the current challenges in the development of robot control systems is making them capable of intelligent and suitable responses to changing environments. But, the control of the robot's behavior in uncertai...
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One of the current challenges in the development of robot control systems is making them capable of intelligent and suitable responses to changing environments. But, the control of the robot's behavior in uncertain and dynamic environments is very challenging when the problem is how to guarantee the robot's safety by minimizing the interaction with other actors. The most popular methods are based on reactive local navigation schemes that tightly couple the robot actions to the sensor information. These approaches are well based on distance between the robot and the obstacles. This information does not allow the robot to make an intelligent decision while it navigates in unknown environments. Whereas, the robot needs to anticipate environment evolution in order to minimize interaction and avoid conflict with other agents. In this paper, we present a multi-agent simulation model of an autonomous robot in dynamic and uncertain environments. We focus on cases of interactions between agents sharing the same space. The robot should minimize the conflict with other agents when it navigates headed for its goal. Our model is based on fuzzy logic technique in order to deal with the uncertainty of perception.
We introduce a new plan repair method for problems cast as Mixed Integer Programs. In order to tackle the inherent complexity of these NP-hard problems, our approach relies on the use of Supervised Learning method for...
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We introduce a new plan repair method for problems cast as Mixed Integer Programs. In order to tackle the inherent complexity of these NP-hard problems, our approach relies on the use of Supervised Learning method for the offline construction of a predictor which takes the problem's parameters as input and infers values for the discrete optimization variables. This way, the online resolution time of the plan repair problem can be greatly decreased by avoiding a large part of the combinatorial search among discrete variables. This contribution was motivated by the large-scale problem of intra-daily recourse strategy computation in electrical power systems. We report and discuss results on this benchmark, illustrating the different aspects and mechanisms of this new approach which provided close-to-optimal solutions in only a fraction of the computational time necessary for existing solvers.
Novel lazy Lauritzen-Spiegelhalter (LS), lazy Hugin and lazy Shafer-Shenoy (SS) algorithms are devised for Gaussian Bayesian networks (BNs). In the lazy algorithms, the clique potentials and separator potentials are k...
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Novel lazy Lauritzen-Spiegelhalter (LS), lazy Hugin and lazy Shafer-Shenoy (SS) algorithms are devised for Gaussian Bayesian networks (BNs). In the lazy algorithms, the clique potentials and separator potentials are kept in combinable decomposed form instead of combined to be a single valuation in conventional junction tree algorithms. By employing decomposed form potentials, the independence relations between variables are explored online and the directed graph information is utilized in the message calculations. In the proposed algorithms, a consistent junction tree with the evidence entered can be obtained by a single round of message passing. The moments form parametrization of Gaussian distributions allows the deterministic relationships between variables. Preliminary analysis shows that the lazy LS algorithm and the lazy Hugin algorithm are more computationally efficient than the lazy SS algorithm, especially when there are multiple items of evidence to be incorporated.
This paper presents Perturbed Frequent Itemset based Classification Technique (PERFICT), a novel associative classification approach based on perturbed frequent itemsets. Most of the existing associative classifiers w...
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This paper presents Perturbed Frequent Itemset based Classification Technique (PERFICT), a novel associative classification approach based on perturbed frequent itemsets. Most of the existing associative classifiers work well on transactional data where each record contains a set of boolean items. They are not very effective in general for relational data that typically contains real valued attributes. In PERFICT, we handle real attributes by treating items as (attribute, value) pairs, where the value is not the original one, but is perturbed by a small amount and is a range based value. We also propose our own similarity measure which captures the nature of real valued attributes and provide effective weights for the itemsets. The probabilistic contributions of different itemsets is taken into considerations during classification. Some of the applications where such a technique is useful are in signal classification, medical diagnosis and handwriting recognition. Experiments conducted on the UCI Repository datasets show that PERFICT is highly competitive in terms of accuracy in comparison with popular associative classification methods.
This work presents the concept of Continuous Search (CS), which objective is to allow any user to eventually get their constraint solver achieving a top performance on their problems. Continuous Search comes in two mo...
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This work presents the concept of Continuous Search (CS), which objective is to allow any user to eventually get their constraint solver achieving a top performance on their problems. Continuous Search comes in two modes: the functioning mode solves the user's problem instances using the current heuristics model; the exploration mode reuses these instances to train and improve the heuristics model through Machine Learning during the computer idle time. Contrasting with previous approaches, Continuous Search thus does not require that the representative instances needed to train a good heuristics model be available beforehand. It achieves lifelong learning, gradually becoming an expert on the user's problem instance distribution. Experimental validation suggests that Continuous Search can design efficient mixed strategies after considering a moderate number of problem instances.
This paper proposes three methods for combining various probabilistic models for retrieving answers from community-based question answering (cQA) archives. We adopt four probabilistic models for these combinations, i....
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This paper proposes three methods for combining various probabilistic models for retrieving answers from community-based question answering (cQA) archives. We adopt four probabilistic models for these combinations, i.e., (1) the language model measuring similarity between a query and a question stored in the cQA archive, (2) two translation models for measuring the similarity between a query and an answer stored in the cQA archive, and a background language model for smoothing. Then, we developed three parameter estimation methods. Two of them are mixture models of the language models. The remaining model exploits the difference between the models. We apply the proposed methods to a cQA archive and show that they significantly outperform a widely used language model and Okapi BM25. We also show that they achieve a better performance than the recently proposed cQA retrieval method.
This paper presents a hybrid intelligent method to design Morphological-Rank-Linear (MRL) perceptrons to solve the Software Development Cost Estimation (SDCE) problem. The proposed method uses a modified genetic algor...
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This paper presents a hybrid intelligent method to design Morphological-Rank-Linear (MRL) perceptrons to solve the Software Development Cost Estimation (SDCE) problem. The proposed method uses a modified genetic algorithm (MGA) to determine the best particular features to improve the MRL perceptron performance, as well as its initial parameters. Furthermore, for each individual of MGA, a gradient steepest descent method is used to optimize the MRL perceptron parameters supplied by MGA. An experimental analysis is conducted with the proposed method using the Desharnais and Cocomo databases. In the experiments, two relevant performance metrics and a fitness function are used to assess the performance of the proposed method. The results obtained are compared to methods recently presented in literature.
A new method is presented which combines a deterministic analytical method and a probabilistic measure to classify rock types on the basis of their hyperspectral curve shape. This method is a supervised learning algor...
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A new method is presented which combines a deterministic analytical method and a probabilistic measure to classify rock types on the basis of their hyperspectral curve shape. This method is a supervised learning algorithm using Gaussian Processes (GPs) and the Observation Angle Dependent (OAD) covariance function. The OAD covariance function makes use of the properties of the Spectral Angle Mapper (SAM) which is used frequently for classifying hyperspectral data. Results show that it is possible to identify and classify rocks in an `One vs. One' and an `One vs. All' approach using the entire spectral curve (0.35-2.5 μm). The results show an average classification accuracy of 98% and an F-score of 92% for the new method in an `One vs. All' approach. Slightly higher classification accuracy and F-measure for the new method can be achieved for the `One vs. One' binary approach. This paper extends the ideas of the deterministic SAM method to a probabilistic framework and enables data fusion with similar and disparate kinds of sensors. This paper demonstrates a superior classification performance of the new probabilistic method over the classical SAM.
We demonstrated logic gates based on complementary carbon nanotube field-effect transistors (CNT-FETs) with SiNx passivation films deposited by catalytic chemical vapor deposition. The carrier type of CNT-FETs was con...
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We demonstrated logic gates based on complementary carbon nanotube field-effect transistors (CNT-FETs) with SiNx passivation films deposited by catalytic chemical vapor deposition. The carrier type of CNT-FETs was controlled by forming SiNx passivation films. Electrical measurements revealed that the p-type characteristics of CNT-FETs were converted to n-type characteristics after the deposition of SiNx passivation films. Then, the n-type CNT-FETs with SiNx passivation films were reconverted to p-type CNT-FETs by annealing in N-2 atmosphere. As a consequence, complementary voltage inverters comprising p-and n-type CNT-FETs with SiNx passivation films were demonstrated on the same SiO2 substrate by conventional photolithography and lift-off techniques. Moreover, the static transfer and dynamic characteristics of the CNT-FET-based inverters were investigated. It was found that a gain of approximately 3 was achieved and that the device was switched properly at frequencies of up to 100 Hz. (C) 2010 The Japan Society of Applied Physics
Coinduction has recently been introduced into logicprogramming by Simon et al. The resulting paradigm, termed coinductive logicprogramming (co-LP), allows one to model and reason about infinite processes and objects...
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