Knowledge-based product support systems

This research helps bridge the gap between conventional product support, where the support system is considered as a stand-alone application, and the new paradigm of responsive one, where the support system frequently communicates with its environment and reacts to stimuli. This new paradigm would enable product support knowledge to be captured, stored, processed, and updated automatically, being delivered to the users when, where and in the form they need it. The research reported in this thesis first defines Product Support Systems (PRSSs) as electronic means that provide accurate and up-to-date information to the user in a coherent and personalised manner. Product support knowledge is then identified as the integration of product, task, user, and support documentation knowledge. Next, the thesis focuses on an ontology-based model of the structure, relations, and attributes of product support knowledge. In that model product support virtual documentation (PSVD) is presented as an aggregation of Information Objects (IOs) and Information Object Clusters (IOCs). The description of PSVD is followed by an analysis of the relation between IOs, IOCs, and domain knowledge. Then, the thesis builds on the ontology-based representation of product support knowledge and explores the synergy between product support, problem solving, and knowledge engineering. As a result, a structured problem solving approach is introduced that combines case-based adaptation and model-based generation techniques. Based on that approach a knowledge engineering framework for product support systems is developed. A conceptual model of context-aware product support systems that extends the framework is then introduced. The conceptual model includes an ontology-based representation of knowledge related to the users, their activities, the support environment, and the device being used. An approach to semi-automatically integrating design and documentation data is also proposed as part of context-aware product support systems development process.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Knowledge-based product support systems

This research helps bridge the gap between conventional product support, where the support system is considered as a stand-alone application, and the new paradigm of responsive one, where the support system frequently communicates with its environment and reacts to stimuli. This new paradigm would enable product support knowledge to be captured, stored, processed, and updated automatically, being delivered to the users when, where and in the form they need it. The research reported in this thesis first defines Product Support Systems (PRSSs) as electronic means that provide accurate and up-to-date information to the user in a coherent and personalised manner. Product support knowledge is then identified as the integration of product, task, user, and support documentation knowledge. Next, the thesis focuses on an ontology-based model of the structure, relations, and attributes of product support knowledge. In that model product support virtual documentation (PSVD) is presented as an aggregation of Information Objects (IOs) and Information Object Clusters (IOCs). The description of PSVD is followed by an analysis of the relation between IOs, IOCs, and domain knowledge. Then, the thesis builds on the ontology-based representation of product support knowledge and explores the synergy between product support, problem solving, and knowledge engineering. As a result, a structured problem solving approach is introduced that combines case-based adaptation and model-based generation techniques. Based on that approach a knowledge engineering framework for product support systems is developed. A conceptual model of context-aware product support systems that extends the framework is then introduced. The conceptual model includes an ontology-based representation of knowledge related to the users, their activities, the support environment, and the device being used. An approach to semi-automatically integrating design and documentation data is also proposed as part of context-aware product support systems development process

The statistical analysis plan for the unification of treatments and interventions for tinnitus patients randomized clinical trial (UNITI-RCT)

Background Tinnitus is a leading cause of disease burden globally. Several therapeutic strategies are recommended in guidelines for the reduction of tinnitus distress; however, little is known about the potentially increased effectiveness of a combination of treatments and personalized treatments for each tinnitus patient. Methods Within the Unification of Treatments and Interventions for Tinnitus Patients project, a multicenter, randomized clinical trial is conducted with the aim to compare the effectiveness of single treatments and combined treatments on tinnitus distress (UNITI-RCT). Five different tinnitus centers across Europe aim to treat chronic tinnitus patients with either cognitive behavioral therapy, sound therapy, structured counseling, or hearing aids alone, or with a combination of two of these treatments, resulting in four treatment arms with single treatment and six treatment arms with combinational treatment. This statistical analysis plan describes the statistical methods to be deployed in the UNITI-RCT. Discussion The UNITI-RCT trial will provide important evidence about whether a combination of treatments is superior to a single treatment alone in the management of chronic tinnitus patients. This pre-specified statistical analysis plan details the methodology for the analysis of the UNITI trial results. Trial registration ClinicalTrials.gov NCT04663828. The trial is ongoing. Date of registration: December 11, 2020. All patients that finished their treatment before 19 December 2022 are included in the main RCT analysis

Comparison of euroscore and care score in heart surgery

Introduction: The aim of this single-center study was to assess the predictive value of two risk stratification systems, the Logistic Euroscore and the CARE (Cardiac Anesthesia Risk Evaluation score) in a Greek population who underwent open cardiac surgery. Method: From March 2005 to December 2006 both scores were applied to 301 adult patients who underwent elective or emergency open cardiac surgery in our hospital. Data was collected prospectively by two anaesthesiologists according to the criteria and definitions described by the two model developers. Two outcomes were examined: 30 day mortality and length of hospital stay. Random cross-checking was performed to minimise interobserver errors. Calibration was determined by Hosmer-Lemeshow goodness of fit statistics (HL). Discrimination was assessed by using receiver operating characteristic (ROC) curves. Results:Both systems predicted 30 day mortality reliably. The area under receiver operating characteristic (ROC) curves was 0,80 (95% C.I. 0,69-0,90 ) for the Logistic Euroscore and 0,78 (95% C.I. 0,66-0,89) for the CARE. The calibration analysis showed agreement between the observed and expected number of deaths, with both models. None of the two models showed the same discriminating ability for length of hospital stay: 0,54 (95% C.I. 0,51-0,65) for the Logistic Euro score and 0,56 (95% C.I. 0,49- 0,63) for the Care. Conclusions: The CARE score predicted 30 day mortality as well as the Logistic Euro SCORE in this Greek population. Both of these systems were unable to predict length of hospital stay.Σκοπός: Σκοπός της μελέτης ήταν η συγκριτική αξιολόγηση της προγνωστικής αξίας των συστημάτων Cardiac Anesthesia Risk Evaluation score (CARE) και του Logistic European System for Cardiac Operative Risk Evaluation (EURO SCORE) σε ασθενείς ενός Καρδιοχειρουργικού κέντρου σε ότι αφορά την πρώιμη θνητότητα και τη διάρκεια νοσηλείας τους στο νοσοκομείο μας. Υλικό και μέθοδος: Από το Μάρτιο του 2005 έως το Δεκέμβριο του 2006 μελετήθηκαν 301 ασθενείς που υποβλήθηκαν σε εκλεκτική ή επείγουσα επέμβαση στο νοσοκομείου μας. Τα δεδομένα των ασθενών συγκεντρώθηκαν από δύο αναισθησιολόγους, σύμφωνα με τα κριτήρια και τους ορισμούς που δόθηκαν από τους συγγραφείς που ανέπτυξαν τα δύο συστήματα αξιολόγησης. Κατά την άμεση προεγχειρητική περίοδο οι ασθενείς ταξινομήθηκαν σύμφωνα με το ιστορικό τους, τον κλινικό έλεγχο και τα προεγχειρητικά τους ευρήματα στα δύο συστήματα προεγχειρητικής αξιολόγησης. Συγκρίθηκε η προβλεπόμενη θνητότητα και η διάρκεια νοσηλείας. Ως διαγνωστικό κριτήριο για την καλή προσαρμογή των συστημάτων, χρησιμοποιήθηκε ο έλεγχος των Hosmer-Lemeshow, ενώ με τη βοήθεια της καμπύλης ROC έγινε η σύγκριση της διαγνωστικής τους ικανότητας. Αποτελέσματα: Η αντιστοιχία μεταξύ παρατηρούμενων και προβλεπόμενων θανάτων κατά τον έλεγχο Hosmer-Lemeshow ήταν ικανοποιητική. Για τη θνητότητα το εμβαδόν της επιφάνειας κάτω από την καμπύλη ROC ήταν 0.80 (95% C.I. 0.69-0.90) για το Euro SCORE και 0.78 (95% C.I. 0.66-0.89) για το Care, υποδηλώνοντας ικανοποιητική διαχωριστική ικανότητα για τα δύο συστήματα. Αντίθετα και τα δύο συστήματα δεν έδειξαν την ίδια διαχωριστική ικανότητα για την διάρκεια νοσηλείας (οι καμπύλες ROC ήταν 0.54 (95% C.I. 0.51-0.65) για το Euro SCORE και 0.56 (95% C.I. 0.49-0.63) για το Care. Συμπεράσματα: Τόσο Care όσο και το Logistic Euro SCORE μπορούν εξίσου να προβλέψουν τη θνητότητα στους καρδιοχειρουργικούς ασθενείς στην περιοχή μας, δεν συμβαίνει όμως το ίδιο με την προγνωστική τους αξία όσο αφορά τη διάρκεια νοσηλείας

Adaptive, responsive and reconfigurable product support for future manufacturing

The challenge for future manufacturing will be not only how to design new families of customized products and capacities for producing them, but also how to provide product support that is both highly customized and highly responsive. The aim of this paper is to address this challenge and facilitate the move towards reconfigurable manufacturing by providing manufacturing industry and research with an integrated approach to developing highly customized and responsive product support for the next generation of complex and highly customized products. The paper presents the key features of the proposed approach, its enabling technologies, architecture and development phases. These include development of training materials and their integration with the automation system, integration of the training materials with the diagnostic modules, and provision of context-aware training. The approach is illustrated with examples from the automotive industry

Theoretical study of the photonic materials for solar cells and sensors

The increasing progress of Nanotechnology and Biology focuses increasingly on developing nanoparticles detectors for biological molecules. The approach through "optical methods" ofthis option presents several advantages characteristic of this small size of the device and high sensitivity. In this context, photonic sensors have been for several years a testing ground, particularly with regards development, and its composition. Like other photonic detectors detect changes in the refractive index of the surrounding medium. Their proven their to detect weak changes 2∙10−3 in a space of 102 and the fact that it can operate makes In this paper we approach the problem of detection utilizing both possibilities.Η ανάγκη για την ύπαρξη εφαρμογών που θα μπορούν να κατηγοριοποιούν μια φυσική ουσία ή να την διαχωρίζουν από ένα σύνολο άλλων με παρεμφερείς όμως χημικές ή φυσικές ιδιότητες στις μέρες μας είναι συνεχής. Η ολοένα αυξανόμενη πρόοδος της Νανοτεχνολογίας και της Βιολογίας εστιάζεται όλο και περισσότερο στην ανάπτυξη αισθητήρων ανίχνευσης νανοσωματιδίων ή και βιολογικών μορίων. Η προσέγγιση μέσω "οπτικών μεθόδων" της δυνατότητας αυτής παρουσιάζει αρκετά πλεονεκτήματα με χαρακτηριστικότερα από αυτά το μικρό μέγεθος της διάταξης και την υψηλή ευαισθησία.Στα πλαίσια αυτά οι φωτονικοί αισθητήρες έχουν αποτελέσει εδώ και αρκετά χρόνια ένα πεδίο δοκιμών κυρίως όσο αφορά την ανάπτυξη και τη σύνθεση τους. Όπως και οι υπόλοιποι φωτονικοί ανιχνευτές εντοπίζουν τις αλλαγές στον δείκτη διάθλασης του περιβάλλοντος μέσου. Η αποδεδειγμένη δυνατότητα τους να εντοπίζουν ασθενείς μεταβολές 2∙10−3σε ένα χώρο διαστάσεων 102 καθώς και το γεγονός πως μπορούν να λειτουργούν είτε σαν κοιλότητες συντονισμού είτε σαν κυματοδηγοί τους καθιστά ιδιαιτέρως σημαντικούς