The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Consider a robot whose task is to pick up some colored balls from a grid, taking the red balls to a red spot, the blue balls to a blue spot and so on, one by one, without knowing either the location or color of the balls but having a sensor that can find out both when a ball is near. This problem is simple and can be solved by a domain-independent contingent planner in principle, but in practice this...
This paper explores an integrated approach to diagnosis of complex dynamic systems. Consistency-based diagnosis is capable of performing automatic fault detection and localization using just correct behaviour models. Nevertheless, it may exhibit low discriminative power among fault candidates. Hence, we combined the consistency based approach with machine learning techniques specially developed for...
This paper addresses the characterization of a large text collection by introducing a method for retrieving sets of relevant WordNet concepts as descriptors of the collection contents. The method combines models for identifying interesting word co-occurrences with an extension of a word sense disambiguation algorithm in order to retrieve the concepts that better fit in with the collection topics....
Collaborative work can be supported by many tools and it has been included in a large number of learning environments design. This paper presents issues related to an educational portal design and collaboration in Intelligent Tutoring Systems (ITS). In order to achieve the collaboration it was necessary to provide a way to interoperate knowledge among the heterogeneous systems. We have been developing...
This paper describes an approach to automatically obtain an HTN planning domain from a well structured learning objects repository and also to apply an HTN planner to obtain IMS Learning Designs adapted to the features and needs of every student.
Generative Topographic Mapping is a probabilistic model for data clustering and visualization. It maps points, considered as prototype representatives of data clusters, from a low dimensional latent space onto the observed data space. In semi-supervised settings, class information can be added resulting in a model variation called class-GTM. The number of class-GTM latent points used is usually large...
This article presents an approach for noise filtering that is based on anisotropic nonlinear diffusion. The method combines edge-preserving noise reduction with a strategy to enhance local structures and a mechanism to further smooth the background. We have provided the method with an automatic mechanism for parameter self-tuning and for stopping the iterative filtering process. The performance of...
This work presents a middle-ware able to translate OWL-S web services descriptions into a temporal HTN domain in order to automatically compose and execute sequences of web service invocations, including parallel branches and complex synchronizations, based on the combination of HTN planning and temporal reasoning techniques.
We consider a job shop problem with uncertain durations and flexible due dates and introduce a multiobjective model based on lexicographical minimisation. To solve the resulting problem, a genetic algorithm and a decoding algorithm to generate possibly active schedules are considered. The multiobjective approach is tested on several problem instances, illustrating the potential of the proposed method.
Being aware of the importance of classifiers to be comprehensible when using machine learning to solve real world problems, bagging needs a way to be explained. This work compares Consolidated Tree’s Construction (CTC) algorithm with the Combined Multiple Models (CMM) method proposed by Domingos when used to extract explanation of the classification made by bagging. The comparison has been done from...
A relaxed setting for Feature Selection is known as Feature Ranking in Machine Learning. The aim is to establish an order between the attributes that describe the entries of a learning task according to their utility. In this paper, we propose a method to establish these orders using Preference Learning by means of Support Vector Machines (SVM). We include an exhaustive experimental study that investigates...
Real-time search methods allow an agent to move in unknown environments. We provide two enhancements to the real-time search algorithm HLRTA*(k). First, we give a better way to perform bounded propagation, generating the HLRTA*LS(k) algorithm. Second, we consider the option of doing more than one action per planning step, by analyzing the quality of the heuristic found during...
In this work a simulated wastewater treatment plant is controlled with a sliding mode control carried out with softcomputing techniques. The controller has two modules: the first one performs the plant control when its dynamics lies inside an optimal working region and is carried out by a neural network trained to reproduce the behavior of the technician who controls an actual plant, while the second...
Many recent successful planners use domain-independent heuristics to speed up the search for a valid plan. An orthogonal approach to accelerating search is to identify and remove redundant operators. We present a domain-independent algorithm for efficiently pruning redundant operators prior to search. The algorithm operates in the domain transition graphs of multi-valued state variables, so its complexity...
We introduce a non-admissible heuristic for planning with action costs, called the set-additive heuristic, that combines the benefits of the additive heuristic used in the HSP planner and the relaxed plan heuristic used in FF. The set-additive heuristic is defined mathematically and handles non-uniform action costs like the additive heuristic ha, and...
There exist various narrative systems, focused on different parts of the complex process of story generation. Some of them are oriented to content planning, and some to sentence planning, with different properties and characteristics. In this paper we propose a system based on BDI agents that generates stories (creating content, performing content planning and simple sentence planning) with narrative...
Models are used in science and engineering for experimentation, analysis, model-based diagnosis, design and planning/sheduling applications. Many of these models are overconstrained Numeric Constraint Satisfaction Problems (NCSP), where the numeric constraints could have linear or polynomial relations. In practical scenarios, it is very useful to know which parts of the overconstrained NCSP instances...
In this paper we present several interest points detectors and we analyze their suitability when used as landmark extractors for vision-based simultaneous localization and mapping (vSLAM). For this purpose, we evaluate the detectors according to their repeatability under changes in viewpoint and scale. These are the desired requirements for visual landmarks. Several experiments were carried out using...
Transformation Based Learning (TBL) is an intensively Machine Learning algorithm frequently used in Natural Language Processing. TBL uses rule templates to identify error-correcting patterns. A critical requirement in TBL is the availability of a problem domain expert to build these rule templates. In this work, we propose an evolutionary approach based on Genetic Algorithms to automatically implement...
We provide upper bounds for the Vapnik-Chervonenkis dimension of classes of subsets of that can be recognized by computer programs built from arithmetical assignments, infinitelydifferentiable algebraic operations (like k-root extraction and, more generally, operations defined by algebraic series of fractional powers), conditional statements and while instructions. This includes certain...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.