The authors present a knowledge retrieval framework for the household domain enhanced with external knowledge sources that can argue over the information that it returns and learn new knowledge through an argumentation dialogue. The framework provides access to commonsense knowledge about household environments and performs semantic matching between entities from the web knowledge graph ConceptNet, using semantic knowledge from DBpedia and WordNet, with the ones existing in the knowledge graph. They offer a set of predefined SPARQL templates that directly address the ontology on which their knowledge retrieval framework is built and querying through SPARQL. The framework also features an argumentation component, where the user can argue against the answers of the knowledge retrieval component of the framework under two different scenarios: the missing knowledge scenario, where an entity should be in the answers, and the wrong knowledge scenario, where an entity should not be in the answers. This argumentation dialogue can end up in learning a new piece of knowledge when the user wins the dialogue.

Localization and navigation is a crucial task of autonomous robots. This paper introduces LadyBug a novel bug algorithm. Using the Received Signal Strength Indication (RSSI) of an electromagnetic signal, the algorithm is able to accurately calculate the position of the beacon emitting the aforementioned signal. Various experiments were performed with a simulated robot equipped only with local sensors. The proposed algorithm was compared with similar approaches with very promising results.

Correctly tuning the hyperparameters of a machine learning model can improve classification results. Typically hyperparameter tuning is made by humans and experience is needed to fine tune them. Algorithmic approaches have been extensively studied in the literature and can find better results. In our work we employ a quantum genetic algorithm to address the hyperparameter optimization problem. The algorithm is based on qudits instead of qubits, allowing more available states. Experiments were performed on two datasets MNIST and CIFAR10 and results were compared against classic genetic algorithms.

Several modern deep learning architectures incorporate the operation of pooling in order to achieve sufficient, minimal and invariant representations. Nevertheless, its importance has only been verified empirically, without solid theoretical evidence. This paper presents a comprehensive theoretical analysis, investigates the mechanism of pooling from the information theory point of view and proposes a novel pooling operation based on entropy. In comparison with other versions of pooling, it automatically adapts to the features and creates more compact representations. The theoretical outcomes are validated utilizing both shallow and deep architectures.

This work aims to advance Web Service retrieval, also known as Matching, in two directions. First, it introduces a matching algorithm for SAWSDL, which adapts and extends known concepts with novel strategies. Effective logic-based and syntactic strategies are introduced and combined in a novel hybrid strategy, targeting an envisioned well-defined, real-world scenario for matching. The algorithm is evaluated in a universal environment for matching algorithms, SME2, in an objective, reproducible manner. Evaluation ranks Tomaco high amongst state of the art, especially for early recall levels (first in macro-averaging precision, up to 0.7 recall). Secondly, this work introduces the Tomaco web application, which aims to promote wide-spread adoption of Semantic Web Services while targeting the lack of user-friendly applications in this field, by integrating a variety of configurable matching algorithms proposed in this paper. It, finally, allows discovery of both existing and user-contributed service collections and ontologies, serving also as a service registry.

The paper presents an integrated approach for automated semantic web service composition using AI planning techniques. An important advantage of this approach is that the composition process, as well as the discovery of the atomic services that take part in the composition, are significantly facilitated by the incorporation of semantic information. OWL-S web service descriptions are transformed into a planning problem described in a standardized fashion using PDDL, while semantic information is used for the enhancement of the composition process as well as for approximating the optimal composite service when exact solutions are not found. Solving, visualization, manipulation, and evaluation of the produced composite services are accomplished, while, unlike other systems, independence from specific planners is maintained. Implementation was performed through the development and integration of two software systems, namely PORSCE II and VLEPPO. PORSCE II is responsible for the transformation process, semantic enhancement, and management of the results. VLEPPO is a general-purpose planning system used to automatically acquire solutions for the problem by invoking external planners. A case study is also presented to demonstrate the functionality, performance, and potential of the approach.

In this paper we present an approach for investigating the feasibility of reducing inference control to access control, as the latter is a more desirable means of preventing unauthorized access to sensitive data. Access control is preferable over inference control in terms of efficiency, but it fails to offer confidentiality in the presence of inference channels. We argue that during the design phase of a data schema and the definition of user roles, inference channels should be considered. An approach is introduced that can be integrated into a risk assessment exercise to assist in determining the roles and/or attributes that lower the risks associated with information disclosure from inference. The residual risk from the remaining inference channels could be treated by well known inference control mechanisms.

This paper presents PORSCE II, a system that combines planning and ontology concept relevance for automatically composing semantic web services. The presented approach includes transformation of the web service composition problem into a planning problem, enhancement with semantic awareness and relaxation and solution through external planners. The produced plans are visualized and their accuracy is assessed.

One of the most promising trends in Domain-Independent AI Planning, nowadays, is state-space heuristic planning. The planners of this category construct general but efficient heuristic functions, which are used as a guide to traverse the state space either in a forward or in a backward direction. Although specific problems may favor one or the other direction, there is no clear evidence why any of them should be generally preferred. This paper presents Hybrid-AcE, a domain-independent planning system that combines search in both directions utilizing a complex criterion that monitors the progress of the search, to switch between them. Hybrid AcE embodies two powerful domain-independent heuristic functions extending one of the AcE planning systems. Moreover, the system is equipped with a fact-ordering technique and two methods for problem simplification that limit the search space and guide the algorithm to the most promising states. The bi-directional system has been tested on a variety of problems adopted from the AIPS planning competitions with quite promising results.

This paper describes Operator Distribution Method for parallel Planning (ODMP), a parallelization method for efficient heuristic planning. The method innovates in that it parallelizes the application of the available operators to the current state and the evaluation of the successor states using the heuristic function. In order to achieve better load balancing and a lift in the scalability of the algorithm, the operator set is initially enlarged, by grounding the first argument of each operator. Additional load balancing is achieved through the reordering of the operator set, based on the expected amount of imposed work. ODMP is effective for heuristic planners, but it can be applied to planners that embody other search strategies as well. It has been applied to GRT, a domain-independent heuristic planner, and CL, a heuristic planner for simple logistics problems, and has been thoroughly tested on a set of logistics problems adopted from the AIPS-98 planning competition, giving quite promising results.