To predict the aeroengine exhaust gas temperature (EGT) more precisely, a process neuron with time-varying threshold function is proposed in this paper, and then the time-varying threshold process neural network model...
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ISBN:
(纸本)9783037858882
To predict the aeroengine exhaust gas temperature (EGT) more precisely, a process neuron with time-varying threshold function is proposed in this paper, and then the time-varying threshold process neural network model comprised of the presented process neurons is used for EGT prediction. By introducing a group of appropriate orthogonal basis functions, the input functions, the weight functions and the threshold functions of the time-varying threshold process neural network can be expanded as linear combinations of the given orthogonal basis functions, thus to eliminate the integration operation, then to simplify the time aggregation operation. The corresponding learning algorithm is also presented, and the effectiveness of the time-varying threshold process neural network model is evaluated through the prediction of EGT series from practical aeroengine condition monitoring.
Objective: Developing a two-step method for formative evaluation of statistical Ontology learning (OL) algorithms that leverages existing biomedical ontologies as reference standards. Methods: In the first step optimu...
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Objective: Developing a two-step method for formative evaluation of statistical Ontology learning (OL) algorithms that leverages existing biomedical ontologies as reference standards. Methods: In the first step optimum parameters are established. A 'gap list' of entities is generated by finding the set of entities present in a later version of the ontology that are not present in an earlier version of the ontology. A named entity recognition system is used to identify entities in a corpus of biomedical documents that are present in the 'gap list', generating a reference standard. The output of the algorithm (new entity candidates), produced by statistical methods, is subsequently compared against this reference standard. An OL method that performs perfectly will be able to learn all of the terms in this reference standard. Using evaluation metrics and precision-recall curves for different thresholds and parameters, we compute the optimum parameters for each method. In the second step, human judges with expertise in ontology development evaluate each candidate suggested by the algorithm configured with the optimum parameters previously established. These judgments are used to compute two performance metrics developed from our previous work: Entity Suggestion Rate (ESR) and Entity Acceptance Rate (EAR). Results: Using this method, we evaluated two statistical OL methods for OL in two medical domains. For the pathology domain, we obtained 49% ESR, 28% EAR with the Lin method and 52% ESR, 39% EAR with the Church method. For the radiology domain, we obtain 87% ESA, 9% EAR using Lin method and 96% ESR, 16% EAR using Church method. Conclusion: This method is sufficiently general and flexible enough to permit comparison of any OL method for a specific corpus and ontology of interest.
Locomotion automation is a very challenging and complex problem to solve. Besidesthe obvious navigation problems, there are also problems regarding the environmentin which navigation has to be performed. Terrains with...
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Locomotion automation is a very challenging and complex problem to solve. Besidesthe obvious navigation problems, there are also problems regarding the environmentin which navigation has to be performed. Terrains with obstacles such as rocks, stepsor high inclinations, among others, pose serious difficulties to normal wheeled *** flexibility of legged locomotion is ideal for these types of terrains but thisalternate form of locomotion brings with it its own challenges to be solved, causedby the high number of degrees of freedom inherent to *** problem is usually computationally intensive, so an alternative, using simpleand hardware amenable bio-inspired systems, was studied. The goal of this thesiswas to investigate if using a biologically inspired learning algorithm, integrated in afully biologically inspired system, can improve its performance on irregular terrainby adapting its gait to deal with obstacles in its *** first, two different versions of a learning algorithm based on unsupervised reinforcementlearning were developed and evaluated. These systems worked by correlatingdifferent events and using them to adjust the behaviour of the system so that itpredicts difficult situations and adapts to them beforehand. The difference betweenthese versions was the implementation of a mechanism that allowed for some correlationsto be forgotten and suppressed by stronger ***, a depth from motion system was tested with unsatisfactory results. Thesource of the problems are analysed and discussed. An alternative system based onstereo vision was implemented, together with an obstacle detection system based onneuron and synaptic models. It is shown that this system is able to detect obstaclesin the path of the *** the individual systems were completed, they were integrated together and thesystem performance was evaluated in a series of 3D simulations using various *** simulations allowed to conclude that both learning systems wer
Neuro-fuzzy systems have been proposed for different applications for many years. In this paper, a k-NN based neuro-fuzzy predictor is developed for time series prediction. We use a neuro-fuzzy system to generate pred...
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Neural networks have already been successfully applied to model the real world problems. The current research attempts to employ architecture of artificial neural networks for approximating solution of a system of fuz...
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Neural networks have already been successfully applied to model the real world problems. The current research attempts to employ architecture of artificial neural networks for approximating solution of a system of fuzzy equations. For this aim, a multi-layer fuzzified feed-forward neural network (FFNN) on the real connection weights space is used. The proposed neural network architecture is able to approximate the unknowns by using a supervised learning algorithm which is based on the gradient descent method. The given approach has been illustrated by several examples with computer simulations.
In this paper we introduce the design aspects of the modified genetic algorithm to be integrated into a computerized assessment tool for school readiness. We describe the needed data structures to store the informatio...
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In this paper we introduce the design aspects of the modified genetic algorithm to be integrated into a computerized assessment tool for school readiness. We describe the needed data structures to store the information as a preparation step for the learning procedure. Then we describe the structure of the chromosomes and the algorithms involved in the creation procedure of the chromosome population. We integrate the constraints forced on the system by the specialists’ requirements and we finally devise the formulas to computing the fitness of each chromosome in the population to the user's needs.
In this paper, we wish to find a minimal data size in order to better conceptualize industrial maintenance activities. We based our study on data given by a Synthetic Hidden Markov Model. This synthetic model is inten...
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In this paper, we wish to find a minimal data size in order to better conceptualize industrial maintenance activities. We based our study on data given by a Synthetic Hidden Markov Model. This synthetic model is intended to produce real industrial maintenance observations (or “symbols”), with a corresponding degradation indicator. These time series events are shown as Markov chains, also called “signatures”. The production of symbols is generated by using a uniform and a normal distribution. The evaluation is made by applying Shannon entropy on the HMM parameters. The results show a minimal number of data for each distribution studied. After a discussion about the use of a new “Sliding Window” of symbols usable in a Computerized Maintenance Management System, we developed two industrial applications and compare them with the best optimized “signature” previously found.
This paper focuses on learning algorithms for approximating functional data that are chosen from some Hilbert spaces. An effective algorithm, called Hilbert parallel overrelaxation backpropagation (HPORBP) algorithm, ...
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This paper focuses on learning algorithms for approximating functional data that are chosen from some Hilbert spaces. An effective algorithm, called Hilbert parallel overrelaxation backpropagation (HPORBP) algorithm, is proposed for training the Hilbert feedforward neural networks that are extensions of feedforward neural networks from Euclidean space Rn to some Hilbert spaces. Furthermore, the convergence of the iterative HPORBP algorithm is analyzed, and a deterministic convergence theorem is proposed for the HPORBP algorithm on the basis of the perturbation results of Mangasarian and Solodov. Some experimental results of learning functional data on some Hilbert spaces illustrate the convergence theorem and show that the proposed HPORBP algorithm has a better accuracy than the Hilbert backpropagation algorithm. Copyright (c)?2012 John Wiley & Sons, Ltd.
This letter investigates an iterative learning control with advanced output data (ADILC) scheme for non-minimum phase (NMP) systems when the number of NMP zeros is unknown. ADILC has a simple learning structure that c...
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This letter investigates an iterative learning control with advanced output data (ADILC) scheme for non-minimum phase (NMP) systems when the number of NMP zeros is unknown. ADILC has a simple learning structure that can be applied to both minimum phase and NMP systems. However, in the latter case, it is assumed that the number of NMP zeros is already known. In this paper, we propose an ADILC scheme in which the number of NMP zeros is unknown. Based on input-to-output mapping, the learning starts from the relative degree. When the input becomes larger than a certain upper bound, we redesign the input update law which consists of the relative degree and the estimated value for the number of NMP zeros.
Aiming at the problem that it is difficult for BP algorithm to converge because of more parameters in training of process neural networks based on orthogonal basis expansion, a quantum shuffled frog leaping algorithm ...
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ISBN:
(纸本)9781479905607
Aiming at the problem that it is difficult for BP algorithm to converge because of more parameters in training of process neural networks based on orthogonal basis expansion, a quantum shuffled frog leaping algorithm is presented which combines the quantum theory and is to train the process neural network. In this algorithm, the individuals are expressed with Bloch spherical coordinates of qubits. The quantum individuals are updated by quantum rotation gates, and the mutation of individuals is achieved with Hadamard gates. For the size and direction of rotation angle of quantum rotation gates, a simple determining method is proposed. Above operations extend the search of the solution space effectively. To predict sunspot as an example to validate the presented algorithm.
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