881 resultados para fuzzy logic control


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Pós-graduação em Agronegócio e Desenvolvimento - Tupã

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The pharmaceutical industry was consolidated in Brazil in the 1930s, and since then has become increasingly competitive. Therefore the implementation of the Toyota Production System, which aims to lean production, has become common among companies in the segment. The main efficiency indicator currently used is the Overall Equipment Effectiveness (OEE). This paper intends to, using the fuzzy model DEA-BCC, analyze the efficiency of the production lines of a pharmaceutical company in the Paraíba Valley, compare the values obtained by the model with those calculated by the OEE, identify the most sensitive machines to variation in the data input and develop a ranking of effectiveness between the consumer machinery. After the development, it is shown that the accuracy of the relationship between the two methods is approximately 57% and the line considered the most effective by the Toyota Production System is not the same as the one found by this paper

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Pós-graduação em Engenharia Mecânica - FEG

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The pharmaceutical industry was consolidated in Brazil in the 1930s, and since then has become increasingly competitive. Therefore the implementation of the Toyota Production System, which aims to lean production, has become common among companies in the segment. The main efficiency indicator currently used is the Overall Equipment Effectiveness (OEE). This paper intends to, using the fuzzy model DEA-BCC, analyze the efficiency of the production lines of a pharmaceutical company in the Paraíba Valley, compare the values obtained by the model with those calculated by the OEE, identify the most sensitive machines to variation in the data input and develop a ranking of effectiveness between the consumer machinery. After the development, it is shown that the accuracy of the relationship between the two methods is approximately 57% and the line considered the most effective by the Toyota Production System is not the same as the one found by this paper

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Pós-graduação em Engenharia Mecânica - FEG

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Backgrounds Ea aims: The boundaries between the categories of body composition provided by vectorial analysis of bioimpedance are not well defined. In this paper, fuzzy sets theory was used for modeling such uncertainty. Methods: An Italian database with 179 cases 18-70 years was divided randomly into developing (n = 20) and testing samples (n = 159). From the 159 registries of the testing sample, 99 contributed with unequivocal diagnosis. Resistance/height and reactance/height were the input variables in the model. Output variables were the seven categories of body composition of vectorial analysis. For each case the linguistic model estimated the membership degree of each impedance category. To compare such results to the previously established diagnoses Kappa statistics was used. This demanded singling out one among the output set of seven categories of membership degrees. This procedure (defuzzification rule) established that the category with the highest membership degree should be the most likely category for the case. Results: The fuzzy model showed a good fit to the development sample. Excellent agreement was achieved between the defuzzified impedance diagnoses and the clinical diagnoses in the testing sample (Kappa = 0.85, p < 0.001). Conclusions: fuzzy linguistic model was found in good agreement with clinical diagnoses. If the whole model output is considered, information on to which extent each BIVA category is present does better advise clinical practice with an enlarged nosological framework and diverse therapeutic strategies. (C) 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

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Máster Universitario en Sistemas Inteligentes y Aplicaciones Numéricas en Ingeniería (SIANI)

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La ricerca presentata è un’ampia esplorazione delle possibili applicazioni di concetti, metodi e procedure della Fuzzy Logic all’Ingegneria dei Materiali. Tale nuovo approccio è giustificato dalla inadeguatezza dei risultati conseguiti con i soli metodi tradizionali riguardo alla reologia ed alla durabilità, all’utilizzo di dati di laboratorio nella progettazione e alla necessità di usare un linguaggio (informatizzabile) che consenta una valutazione congiunta degli aspetti tecnici, culturali, economici, paesaggistici della progettazione. – In particolare, la Fuzzy Logic permette di affrontare in modo razionale l’aleatorietà delle variabili e dei dati che, nel settore specifico dei materiali in opera nel costruito dei Beni Culturali, non possono essere trattati con i metodi statistici ordinari. – La scelta di concentrare l’attenzione su materiali e strutture in opera in siti archeologici discende non solo dall’interesse culturale ed economico connesso ai sempre più numerosi interventi in questo nuovo settore di pertinenza dell’Ingegneria dei Materiali, ma anche dal fatto che, in tali contesti, i termini della rappresentatività dei campionamenti, della complessità delle interazioni tra le variabili (fisiche e non), del tempo e quindi della durabilità sono evidenti ed esasperati. – Nell’ambito di questa ricerca si è anche condotto un ampio lavoro sperimentale di laboratorio per l’acquisizione dei dati utilizzati nelle procedure di modellazione fuzzy (fuzzy modeling). In tali situazioni si è operato secondo protocolli sperimentali standard: acquisizione della composizione mineralogica tramite diffrazione di raggi X (XRD), definizione della tessitura microstrutturale con osservazioni microscopiche (OM, SEM) e porosimetria tramite intrusione forzata di mercurio (MIP), determinazioni fisiche quali la velocità di propagazione degli ultrasuoni e rotoviscosimetria, misure tecnologiche di resistenza meccanica a compressione uniassiale, lavorabilità, ecc. – Nell’elaborazione dei dati e nella modellazione in termini fuzzy, la ricerca è articolata su tre livelli: a. quello dei singoli fenomeni chimico-fisici, di natura complessa, che non hanno trovato, a tutt’oggi, una trattazione soddisfacente e di generale consenso; le applicazioni riguardano la reologia delle dispersioni ad alto tenore di solido in acqua (calci, cementi, malte, calcestruzzi SCC), la correlazione della resistenza a compressione, la gelività dei materiali porosi ed alcuni aspetti della durabilità del calcestruzzo armato; b. quello della modellazione della durabilità dei materiali alla scala del sito archeologico; le applicazioni presentate riguardano i centri di cultura nuragica di Su Monte-Sorradile, GennaMaria-Villanovaforru e Is Paras-Isili; c. quello della scelta strategica costituita dalla selezione del miglior progetto di conservazione considerando gli aspetti connessi all’Ingegneria dei Materiali congiuntamente a quelli culturali, paesaggistici ed economici; le applicazioni hanno riguardato due importanti monumenti (Anfiteatro e Terme a Mare) del sito Romano di Nora-Pula.

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Several activities were conducted during my PhD activity. For the NEMO experiment a collaboration between the INFN/University groups of Catania and Bologna led to the development and production of a mixed signal acquisition board for the Nemo Km3 telescope. The research concerned the feasibility study for a different acquisition technique quite far from that adopted in the NEMO Phase 1 telescope. The DAQ board that we realized exploits the LIRA06 front-end chip for the analog acquisition of anodic an dynodic sources of a PMT (Photo-Multiplier Tube). The low-power analog acquisition allows to sample contemporaneously multiple channels of the PMT at different gain factors in order to increase the signal response linearity over a wider dynamic range. Also the auto triggering and self-event-classification features help to improve the acquisition performance and the knowledge on the neutrino event. A fully functional interface towards the first level data concentrator, the Floor Control Module, has been integrated as well on the board, and a specific firmware has been realized to comply with the present communication protocols. This stage of the project foresees the use of an FPGA, a high speed configurable device, to provide the board with a flexible digital logic control core. After the validation of the whole front-end architecture this feature would be probably integrated in a common mixed-signal ASIC (Application Specific Integrated Circuit). The volatile nature of the configuration memory of the FPGA implied the integration of a flash ISP (In System Programming) memory and a smart architecture for a safe remote reconfiguration of it. All the integrated features of the board have been tested. At the Catania laboratory the behavior of the LIRA chip has been investigated in the digital environment of the DAQ board and we succeeded in driving the acquisition with the FPGA. The PMT pulses generated with an arbitrary waveform generator were correctly triggered and acquired by the analog chip, and successively they were digitized by the on board ADC under the supervision of the FPGA. For the communication towards the data concentrator a test bench has been realized in Bologna where, thanks to a lending of the Roma University and INFN, a full readout chain equivalent to that present in the NEMO phase-1 was installed. These tests showed a good behavior of the digital electronic that was able to receive and to execute command imparted by the PC console and to answer back with a reply. The remotely configurable logic behaved well too and demonstrated, at least in principle, the validity of this technique. A new prototype board is now under development at the Catania laboratory as an evolution of the one described above. This board is going to be deployed within the NEMO Phase-2 tower in one of its floors dedicated to new front-end proposals. This board will integrate a new analog acquisition chip called SAS (Smart Auto-triggering Sampler) introducing thus a new analog front-end but inheriting most of the digital logic present in the current DAQ board discussed in this thesis. For what concern the activity on high-resolution vertex detectors, I worked within the SLIM5 collaboration for the characterization of a MAPS (Monolithic Active Pixel Sensor) device called APSEL-4D. The mentioned chip is a matrix of 4096 active pixel sensors with deep N-well implantations meant for charge collection and to shield the analog electronics from digital noise. The chip integrates the full-custom sensors matrix and the sparsifification/readout logic realized with standard-cells in STM CMOS technology 130 nm. For the chip characterization a test-beam has been set up on the 12 GeV PS (Proton Synchrotron) line facility at CERN of Geneva (CH). The collaboration prepared a silicon strip telescope and a DAQ system (hardware and software) for data acquisition and control of the telescope that allowed to store about 90 million events in 7 equivalent days of live-time of the beam. My activities concerned basically the realization of a firmware interface towards and from the MAPS chip in order to integrate it on the general DAQ system. Thereafter I worked on the DAQ software to implement on it a proper Slow Control interface of the APSEL4D. Several APSEL4D chips with different thinning have been tested during the test beam. Those with 100 and 300 um presented an overall efficiency of about 90% imparting a threshold of 450 electrons. The test-beam allowed to estimate also the resolution of the pixel sensor providing good results consistent with the pitch/sqrt(12) formula. The MAPS intrinsic resolution has been extracted from the width of the residual plot taking into account the multiple scattering effect.

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Nell’attuale contesto di aumento degli impatti antropici e di “Global Climate Change” emerge la necessità di comprenderne i possibili effetti di questi sugli ecosistemi inquadrati come fruitori di servizi e funzioni imprescindibili sui quali si basano intere tessiture economiche e sociali. Lo studio previsionale degli ecosistemi si scontra con l’elevata complessità di questi ultimi in luogo di una altrettanto elevata scarsità di osservazioni integrate. L’approccio modellistico appare il più adatto all’analisi delle dinamiche complesse degli ecosistemi ed alla contestualizzazione complessa di risultati sperimentali ed osservazioni empiriche. L’approccio riduzionista-deterministico solitamente utilizzato nell’implementazione di modelli non si è però sin qui dimostrato in grado di raggiungere i livelli di complessità più elevati all’interno della struttura eco sistemica. La componente che meglio descrive la complessità ecosistemica è quella biotica in virtù dell’elevata dipendenza dalle altre componenti e dalle loro interazioni. In questo lavoro di tesi viene proposto un approccio modellistico stocastico basato sull’utilizzo di un compilatore naive Bayes operante in ambiente fuzzy. L’utilizzo congiunto di logica fuzzy e approccio naive Bayes è utile al processa mento del livello di complessità e conseguentemente incertezza insito negli ecosistemi. I modelli generativi ottenuti, chiamati Fuzzy Bayesian Ecological Model(FBEM) appaiono in grado di modellizare gli stati eco sistemici in funzione dell’ elevato numero di interazioni che entrano in gioco nella determinazione degli stati degli ecosistemi. Modelli FBEM sono stati utilizzati per comprendere il rischio ambientale per habitat intertidale di spiagge sabbiose in caso di eventi di flooding costiero previsti nell’arco di tempo 2010-2100. L’applicazione è stata effettuata all’interno del progetto EU “Theseus” per il quale i modelli FBEM sono stati utilizzati anche per una simulazione a lungo termine e per il calcolo dei tipping point specifici dell’habitat secondo eventi di flooding di diversa intensità.

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La tesi affronta il concetto di esposizione al rischio occupazionale e il suo scopo è quello di indagare l’ambiente di lavoro e il comportamento dei lavoratori, con l'obiettivo di ridurre il tasso di incidenza degli infortuni sul lavoro ed eseguire la riduzione dei rischi. In primo luogo, è proposta una nuova metodologia denominata MIMOSA (Methodology for the Implementation and Monitoring of Occupational SAfety), che quantifica il livello di "salute e sicurezza" di una qualsiasi impresa. Al fine di raggiungere l’obiettivo si è reso necessario un approccio multidisciplinare in cui concetti d’ingegneria e di psicologia sono stati combinati per sviluppare una metodologia di previsione degli incidenti e di miglioramento della sicurezza sul lavoro. I risultati della sperimentazione di MIMOSA hanno spinto all'uso della Logica Fuzzy nel settore della sicurezza occupazionale per migliorare la metodologia stessa e per superare i problemi riscontrati nell’incertezza della raccolta dei dati. La letteratura mostra che i fattori umani, la percezione del rischio e il comportamento dei lavoratori in relazione al rischio percepito, hanno un ruolo molto importante nella comparsa degli incidenti. Questa considerazione ha portato ad un nuovo approccio e ad una seconda metodologia che consiste nella prevenzione di incidenti, non solo sulla base dell'analisi delle loro dinamiche passate. Infatti la metodologia considera la valutazione di un indice basato sui comportamenti proattivi dei lavoratori e sui danni potenziali degli eventi incidentali evitati. L'innovazione consiste nell'applicazione della Logica Fuzzy per tener conto dell’"indeterminatezza" del comportamento umano e del suo linguaggio naturale. In particolare l’applicazione è incentrata sulla proattività dei lavoratori e si prefigge di impedire l'evento "infortunio", grazie alla generazione di una sorta d’indicatore di anticipo. Questa procedura è stata testata su un’azienda petrolchimica italiana.

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An integrated approach for multi-spectral segmentation of MR images is presented. This method is based on the fuzzy c-means (FCM) and includes bias field correction and contextual constraints over spatial intensity distribution and accounts for the non-spherical cluster's shape in the feature space. The bias field is modeled as a linear combination of smooth polynomial basis functions for fast computation in the clustering iterations. Regularization terms for the neighborhood continuity of intensity are added into the FCM cost functions. To reduce the computational complexity, the contextual regularizations are separated from the clustering iterations. Since the feature space is not isotropic, distance measure adopted in Gustafson-Kessel (G-K) algorithm is used instead of the Euclidean distance, to account for the non-spherical shape of the clusters in the feature space. These algorithms are quantitatively evaluated on MR brain images using the similarity measures.

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Because the knowledge in the World Wide Web is continuously expanding, Web Knowledge Aggregation, Representation and Reasoning (abbreviated as KR) is becoming increasingly important. This article demonstrates how fuzzy ontologies can be used in KR to improve the interactions between humans and computers. The gap between the Social and Semantic Web can be reduced, and a Social Semantic Web may become possible. As an illustrative example, we demonstrate how fuzzy logic and KR can enhance technologies for cognitive cities. The underlying notion of these technologies is based on connectivism, which can be improved by incorporating the results of digital humanities research.

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The data acquired by Remote Sensing systems allow obtaining thematic maps of the earth's surface, by means of the registered image classification. This implies the identification and categorization of all pixels into land cover classes. Traditionally, methods based on statistical parameters have been widely used, although they show some disadvantages. Nevertheless, some authors indicate that those methods based on artificial intelligence, may be a good alternative. Thus, fuzzy classifiers, which are based on Fuzzy Logic, include additional information in the classification process through based-rule systems. In this work, we propose the use of a genetic algorithm (GA) to select the optimal and minimum set of fuzzy rules to classify remotely sensed images. Input information of GA has been obtained through the training space determined by two uncorrelated spectral bands (2D scatter diagrams), which has been irregularly divided by five linguistic terms defined in each band. The proposed methodology has been applied to Landsat-TM images and it has showed that this set of rules provides a higher accuracy level in the classification process

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Trillas et al. (1999, Soft computing, 3 (4), 197–199) and Trillas and Cubillo (1999, On non-contradictory input/output couples in Zadeh's CRI proceeding, 28–32) introduced the study of contradiction in the framework of fuzzy logic because of the significance of avoiding contradictory outputs in inference processes. Later, the study of contradiction in the framework of Atanassov's intuitionistic fuzzy sets (A-IFSs) was initiated by Cubillo and Castiñeira (2004, Contradiction in intuitionistic fuzzy sets proceeding, 2180–2186). The axiomatic definition of contradiction measure was stated in Castiñeira and Cubillo (2009, International journal of intelligent systems, 24, 863–888). Likewise, the concept of continuity of these measures was formalized through several axioms. To be precise, they defined continuity when the sets ‘are increasing’, denominated continuity from below, and continuity when the sets ‘are decreasing’, or continuity from above. The aim of this paper is to provide some geometrical construction methods for obtaining contradiction measures in the framework of A-IFSs and to study what continuity properties these measures satisfy. Furthermore, we show the geometrical interpretations motivating the measures.