Search results for "SISTEMI"
showing 10 items of 2026 documents
INTEGRATING ONTOLOGY AND COGNITIVE LINGUISTICS FOR NATURAL LANGUAGE PRODUCTION AND UNDERSTANDING
2012
Ontologies have been designed to capture the semantic knowledge of a domain in a machine understandable form. Current standards for managing ontologies like OWL are lacking in linguistic grounding, and are not able to achieve a clear link with natural language. Bridging this gap, unskilled users could be able to infer the information described in the ontology and it would be possible either producing or parsing utterances about the represented domain automatically. Moreover, as in the case of enterprises, it could be very useful to extract information from external documental corpora that are related to the same domain. Many attempts have been made with the aim to create a natural language …
Object Recognition and Modeling Using SIFT Features
2013
In this paper we present a technique for object recognition and modelling based on local image features matching. Given a complete set of views of an object the goal of our technique is the recognition of the same object in an image of a cluttered environment containing the object and an estimate of its pose. The method is based on visual modeling of objects from a multi-view representation of the object to recognize. The first step consists of creating object model, selecting a subset of the available views using SIFT descriptors to evaluate image similarity and relevance. The selected views are then assumed as the model of the object and we show that they can effectively be used to visual…
Semantics driven interaction using natural language in students tutoring
2007
The aim of this work is to introduce a semantic integration between an ontology and a chatbot in an Intelligent Tutoring Systems (ITS) to interact with students using natural language. The interaction process is driven by the use of a purposely defined ontology. In the ontology two types of conceptual relations are defined. Besides the usual relations, which are used to define the domain's structure, another type of relation is used to define the navigation schema inside the ontology according to the need of managing uncertainty. Uncertainty level is related to student knowledge level about the involved concepts. In this work we propose an ITS for the Java programming language called TutorJ…
Optimal Power Flow in three-phase islanded microgrids with inverter interfaced units
2015
In this paper, the solution of the Optimal Power Flow (OPF) problem for three phase islanded microgrids is studied, the OPF being one of the core functions of the tertiary regulation level for an AC islanded microgrid with a hierarchical control architecture. The study also aims at evaluating the contextual adjustment of the droop parameters used for primary voltage and frequency regulation of inverter interfaced units. The work proposes a mathematical method for the OPF solution also considering the droop parameters as variables. The output of the OPF provides an iso-frequential operating point for all the generation units and a set of droop parameters for primary regulation. In this way, …
Improved primary regulation for minimum energy losses in islanded microgrids
2017
In this paper, an improved primary regulation is proposed for grid forming units supplying islanded microgrids. A minimum losses Optimal Power Flow is run off-line to devise the operating set points composing the primary regulation curve. In this way, after load perturbations, generators can reach an optimized operating point for a given and unique minimum losses energy flows distribution. The idea is to skip the hierarchical control architecture and provide a feasible and optimized operating point. A case study over 24 hours shows the effectiveness of this new approach as well as the improved operation quality of the system.
Optimal pricing strategies in real-time electricity pricing environments: An Italian case study
2015
The energy market has changed radically over the last decade, mainly due to an increased penetration of renewable energies. Now the end users have directly access to the energy market and can actively take part to the electricity market. Electricity customers can indeed modify their behavior through Demand Response (DR), namely by means of pricing strategies that support a change in the end-users habits. This can be accomplished through a 'loads aggregator', a third party that collects the requests and signals for Active Demand-based services coming from the markets and the different power system participants. This paper describes a new framework able to optimally select the real-time prici…
Empirical BAC factors method application to two real case studies in South Italy
2021
Abstract The application of Building Automation and Control (BAC) systems has many advantages. One of these is the reduction of the end-user electricity consumption and, if applied to lighting systems, the achievement of well-acknowledged benefits from daylight, such as productivity, health, visual comfort and well-being. Concerning the first aspect, the international Standard EN 15232 proposes the so-called BAC Factors (BF) method to assess the impact of BAC systems on the final energy consumption. The method provides a simplified estimation of the energy savings due to automation in buildings and questions arise on its applicability in some situations. For this reason, the authors have ca…
Service quality benchmarking via a novel approach based on fuzzy ELECTRE III and IPA: an empirical case involving the Italian public healthcare conte…
2017
A novel fuzzy-based approach which combines ELECTRE III along with the Importance-Performance Analysis (IPA) is proposed in the present work to comparatively evaluate the service quality in the public healthcare context. Specifically, ELECTRE III is firstly considered to compare the service performance of examined hospitals in a noncompensatory manner. Afterwards, IPA is employed to support the service quality management to point out improvement needs and their priorities. The proposed approach also incorporates features of the Fuzzy Set Theory so as to address the possible uncertainty, subjectivity and vagueness of involved experts in evaluating the service quality. The model is applied to…
An algorithm for simulating end-user behaviour in a real time pricing market
2015
The energy market has changed radically over the last decade, mainly due to an increased penetration of renewable energies. Now the end users have directly access to the energy market and can actively take part to the electricity market. Electricity customers can indeed modify their behavior through Demand Response, namely by means of pricing strategies that support a change in the end-users habits. This can be accomplished through a 'loads aggregator', a third party that collects the requests and signals for Active Demand-based services coming from the markets and the different actors of energy market. This paper describes a simulation framework to generate the simulated optimal behavior o…
Technical and economical assessment of distributed electrochemical storages for load shifting applications: An Italian case study
2016
Time-of-use (TOU) energy cost management involves the use of energy storage systems (ESSs) by customers to reduce their electricity bills. The ESS is charged during off-peak time periods, when electricity energy prices are low, and discharged during times when on-peak energy prices are applied. This article addresses the question whether it is economically viable to install medium-scale distributed ESSs designed to lower the electricity cost for a customer-side application, assuming flexible electricity tariffs. The technical/economical evaluation is carried out referring to lithium-ion (Li-ion), sodium sulfur (NaS) and vanadium redox battery (VRB) technologies, performing a parametric anal…