Dissertations / Theses on the topic 'Qualità industriale'

Il controllo di qualità automatico nei processi di produzione è uno degli elementi chiave della quarta rivoluzione industriale che porterà alla creazione della cosiddetta industria 4.0. In questo contesto, un elemento fondamentale è il rilievo di difetti, anomalie o guasti del prodotto in tempo compatibile con quello di produzione. Questa tesi si focalizza esattamente su questo tema: il rilevamento delle anomalie per il controllo automatico di qualità, attraverso l'analisi di immagini raffiguranti il prodotto sotto ispezione. Questa analisi verrà fatta tramite l'utilizzo di tecniche di machine learning, in particolare tramite l'uso di reti neurali convoluzionali (CNN) che sono uno strumento molto potente utilizzato nell'analisi di immagini. In primo luogo questa tesi esegue uno studio estensivo sull'argomento per introdurre il lettore e propone una una sequenza di elaborazioni per il rilevamento automatico di anomalie. Le elaborazioni sono: 1) il miglioramento delle immagini per evidenziare i difetti; 2) il rilievo delle anomalie. La prima elaborazione viene risolta utilizzando una trasformazione colore globale in grado di rimuovere effetti di luce indesiderati ed aumentare il contrasto. Questa trasformazione è ottenuta grazie all'utilizzo di SpliNet, un metodo basato su CNN che viene presentato in questa tesi, che è in grado di migliorare le immagini di input inferendo i parametri di un insieme di spline. La seconda elaborazione, e cioè il rilievo di anomalie, è stata affrontata proponendo due diversi metodi. Il primo ha l'obiettivo di modellare la normalità imparando un dizionario ed utilizzandolo in fase di test per determinare il grado di abnormalità di una immagine incognita. Questo metodo è basato su CNNs, che notoriamente richiedono grandi quantità di dati per essere addestrate. Tuttavia l'algoritmo proposto è in grado di lavorare su un insieme di immagini di addestramento molto piccolo (nell'ordine delle cinque immagini). Il metodo presentato aumenta le performances rispetto allo stato dell'arte relativo al dataset delle nanofibre acquisite con microscopio SEM del 5%, ottenendo un'area sottesa alla curva di 97.4%. Il secondo metodo proposto usa un insieme di trasformazioni locali per restaurare le immagini di input. Specificamente, queste trasformazioni sono un insieme di polinomi di grado due, i cui parametri vengono determinati attraverso l'utilizzo di una rete neurale convoluzionale. Il metodo è progettato in maniera tale che è possibile, attraverso un parametro, modulare l'accuratezza e il tempo di calcolo in maniera tale da soddisfare le esigenze dell'utente finale. Per affrontare la mancanza di dati che affligge il campo del rilievo automatico di anomalie, è stato presentato un metodo innovativo di aumento dei dati basato su deep learning. Questo metodo è in grado di generare migliaia di nuovi campioni sintetici a partire da pochi dati reali e pertanto è particolarmente adatto per aumentare dataset di tipo long-tail. La qualità dei campioni sintetizzati è stata dimostrata misurando l'accuratezza delle performance di algoritmi di machine learning addestrati sul dataset aumentato. Questo metodo è stato utilizzato per espandere un dataset di immagini raffiguranti asfalti difettosi. In questo contesto, l'utilizzo del dataset aumentato ha portato ad un incremento delle performance medie sulla segmentazione di anomalie fino a 17.5 punti percentuali. Nel caso di classi aventi bassa cardinalità, l'aumento arriva fino a 54.5 punti percentuali. Tutti i metodi presentati sovraperformano lo stato dell'arte.
Automatic quality control is one of the key ingredients for the fourth industrial revolution that will lead to the development of the so called industry 4.0. In this context, a crucial element is a production-compatible-time detection of defects, anomalies or product failures. This thesis focuses exactly on this theme: anomaly detection for industrial quality inspection, ensured through the analysis of images depicting the product under inspection. This analysis will be done through the use of machine learning, and especially through the use of convolutional neural networks (CNNs), a powerful instrument used in image analysis. This thesis starts with an extensive study on the subject to introduce the reader and to propose a pipeline for automatic anomaly detection. This pipeline is composed by two steps: 1) the enhancement of the input images for highlighting defects; 2) the detection of the anomalies. The first step is addressed with the use of a global color transformation able to remove undesired light effects and to enhance the contrast. This transformation is inferred through the use of SpliNet, a new CNN-based method here presented, that is able to enhance the input images by inferring the parameters of a set of splines. In the context of anomaly detection, two methods are presented. The first one has the aim of modeling normality by learning a dictionary and using it in test time to determine the degree of abnormality of an inquiry image. This method is based on deep learning, which is known to be data-hungry. However, the proposed algorithm is able to work also on very small trainsets (in the order of five images). The presented method boosts the performances of 5% with respect to the state-of-the art for the SEM-acquired nanofibers dataset, achieving an area under curve of 97.4%. The second proposed algorithm is a generative method able to restore the input, creating an anomaly-free version of the inquiry image. This method uses a set of local transforms to restore the input images. Specifically, these transforms are sets of polynomials of degree two, whose parameters are determined through the use of a convolutional neural network. In this context, the method can be tuned with a parameter toward accuracy or speed, for matching the needs of the final user. To address the lack of data that is suffered in this field, a totally new method for data augmentation based on deep learning is presented. This method is able to generate thousands of new synthesized samples starting from a few and thus is particularly suitable for augmenting long-tail datasets. The quality of the synthesized samples is demonstrated by showing the increase in performance of machine learning algorithms trained on the augmented dataset. This method has been employed to enlarge a dataset of defective asphalts. In this context, the use of the augmented dataset permitted to increase the average performance on anomaly segmentation of up to 17.5 percentage points. In the case of classes having a low cardinality, the improvement is up to 54.5 percentage points. For all the methods here presented I show their effectiveness by analyzing the results with the respective state-of-the-art and show their ability in outperforming the existing methods.

Il presente lavoro di tesi è stato finalizzato a valutare l’influenza di alcuni fattori di produzione sui caratteri quali-quantitativi delle carcasse e delle cosce di suini pesanti destinati alla produzione di prosciutto crudo a Denominazione di Origine Protetta (DOP). La raccolta dati (genotipo, numerosità del lotto, peso vivo e della carcassa, età, resa alla macellazione, classificazione della carcassa secondo la scala SEUROP e delle cosce in funzione della destinazione) è stata condotta presso il Gruppo Alimentare Valtiberino, e ha riguardato complessivamente 190 lotti di suini nel periodo compreso da maggio a dicembre 2021. L’esame dei risultati ha messo in evidenza che il tipo genetico di appartenenza dei suini è il principale fattore in grado di modificare la composizione e il valore della carcassa e delle cosce fresche. In particolare, il peso raggiunto alla macellazione e l’adiposità della carcassa sono risultati piuttosto differenziati fra i tipi genetici considerati, e le carcasse appartenenti ai genotipi caratterizzati da una maggiore percentuale di grasso e minore percentuale in tagli magri hanno mostrato un’elevata predisposizione ad essere utilizzate per la produzione di prosciutto di San Daniele DOP, mentre dagli ibridi commerciali dotati di minore adiposità della carcassa e maggiore resa in tagli magri si ricavano cosce impiegate soprattutto per i prosciutti DOP di Parma o Toscano. La notevole variabilità nei pesi vivi alla macellazione dei suini è risultata, inoltre, strettamente associata alle caratteristiche delle carcasse e delle cosce per la produzione dei prosciutti crudi DOP. In particolare, i suini di peso inferiore ai 170 kg hanno fatto registrare un’elevata incidenza di carcasse (>15%) dotate di adiposità non in linea con quanto previsto dai regolamenti delle DOP, mentre i soggetti di peso superiore ai 180 kg hanno evidenziato un’incidenza di cosce declassate per difetti estetici e di qualità considerevole vicina al 25% del totale.

Questo lavoro si è posto l’obiettivo di valutare come differenti qualità di pellet di legno, in accordo con la norma EN 14961-2, e la diversa potenza termica di una moderna stufa domestica influenzino le relative emissioni prodotte. La norma EN 14961-2 prevede una serie di proprietà per il pellet di legno con valori caratteristici per ogni classe di qualità, A1, A2 e B. Per simulare le condizioni cui sono sottoposte le emissioni in aria ambiente, il campionamento del particolato è stato effettuato per mezzo di un tunnel di diluizione. Per valutare e confrontare le emissioni prodotte della stufa a pellet, i dati ottenuti sono stati espressi come fattori di emissione cioè il rapporto tra la quantità di inquinante emesso e i MJ sviluppati dalla combustione. Dallo studio emerge che il pellet di più scarsa qualità mostra emissioni maggiori di CO, NOx, PM, ioni solubili, e la formazione di IPA con alta tossicità: questo implica un maggior impatto sulla salute dell’uomo e sull’ambiente. Inoltre la combustione di pellet di bassa qualità di tipo B causa frequenti problemi di combustione dovuti all’alta percentuale di ceneri, portando a maggiori emissioni di prodotti da combustione incompleta (TC, IPA, PM). La maggior potenza di funzionamento della stufa limita l’emissione di prodotti di combustione incompleta, TC, CO, PM e IPA, ma aumenta la tossicità di quest’ultimi.

La Tesi fornisce una metodologia per la stima delle emissioni dovute al riscaldamento di sorgenti civili e poter così valutare il loro impatto sulla qualità dell'aria. Tale metodologia è applicata al caso studio della Scuola di Ingegneria e Architettura sita in via Terracini a Bologna. In seguito alla stima delle emissioni, si è proceduto a fare una simulazione della dispersione delle stesse.

Il contributo all’innalzamento del riscaldamento globale, prodotto dai combustibili fossili è un dei principali problemi ambientali. Le bioenergie potrebbero contribuire enormemente alla riduzione di questo fenomeno, sostituendo in parte i combustibili tradizionali di origine fossile. In questo contesto, può collocarsi il biodiesel prodotto a partire da oli vegetali, rappresentando una valida e strategica alternativa. Il biodiesel è una miscela di metil esteri di acidi grassi, [fatty acids methyl esters (FAME)], normalmente ottenuta tramite reazione di transesterificazione tra oli vegetali e alcol a catena corta in presenza di un catalizzatore acido o basico in catalisi sia omogena che eterogenea. Il biodiesel si colloca tra le materie prime di seconda generazione e può risultare una buona base di partenza per ottenere un biodiesel performante e con un basso costo finale.

La presente tesi ha avuto lo scopo di: i) delineare l’evoluzione del mercato avicolo mondiale ed in particolare quello italiano, definendone la storia e gli sviluppi che si sono susseguiti; ii) introdurre il broiler, descriverne le metodiche di allevamento e la legislazione in merito alla sicurezza alimentare e normativa sul benessere del pollo; iii) descrivere il muscolo delle specie avicole, il loro valore nutrizionale, la qualità della carne di pollo e i relativi fattori che la influenzano, quindi i difetti legati al miglioramento genetico con focus sulle anomalie emergenti; iv) valutare l’incidenza globale, l’effetto della stagione e l’effetto del peso di macellazione in relazione alle anomalie emergenti White-Striping, Wooden-Breast e Spaghetti-Meat in uno stabilimento di macellazione e lavorazione del broiler considerando 2900 lotti per un totale di circa 26.643.869 broiler. Nello specifico, i dati ottenuti dallo studio dell’incidenza globale, anche se difficilmente confrontabili con quelli precedenti, hanno evidenziato incidenze medie comprese fra il 6 e l’11% per ciascuna delle tre anomalie emergenti considerate È stato inoltre possibile evidenziare, valutando l’incidenza delle anomalie in relazione ad un intero anno solare, una variazione stagionale delle anomalie WB e SM che hanno evidenziato valori inferiori durante la stagione estiva in parte attribuibile alla riduzione della velocità di accrescimento dei polli, ma che potrebbe essere dovuta a fattori che non sono stati ancora sufficientemente studiati. Sono state inoltre confermate le maggiori criticità, soprattutto per quanto riguarda le anomalie WB e SM riguardanti i polli pesanti che sono macellati a pesi superiori ai 3 kg. Al contrario, i livelli dell’anomalia WS sembrano limitatamente influenzati sia dalla stagionalità che dal peso medio di macellazione dei lotti, al contrario di quanto riscontrato nelle precedenti indagini.

This work presents the results of different numerical and experimental studies about energy performance, thermal comfort and ventilation effectiveness of radiant systems combined with different types of mechanical ventilation. Experimental studies have been carried out in Italy, in a test room in the laboratories of the company RHOSS S.p.A in Codroipo (Udine) and in Denmark, in a test room in the laboratories of the International Centre for Indoor Environment and Energy (ICIEE), at DTU (Danish Technical University), in Lyngby. Radiant systems in residential and in office buildings are increasingly used because of the low heating or cooling demand and, at the same time, for the good thermal comfort they assure. The thermal output estimation of radiant system in steady state condition needs the determination of the convective heat transfer coefficient from the surface to the room; a critical review among the correlations available in literature have been carried out and correlations for heated ceiling and cooled floor have been presented. Furthermore the variation of convective heat transfer coefficients, depending on the considered ventilation systems, has been estimated by means of the Computational Fluid Dynamics (CFD) technique. The energy performance and thermal behavior of radiant systems during transient conditions have been predicted by using experimental tests and numerical calculations with the software Digithon that was developed by the University of Padua. In this work the validation of this software by comparison with experimental data has been presented. In new and renovated buildings the high tightness and high insulation determine a potential risk of poor indoor air quality and condensation at the surfaces; for this reason an efficient ventilation system is necessary to provide for fresh air in the rooms. In a low polluted building air quality depends on human bioeffluents, among which carbon dioxide is considered the most significant one. By using numerical simulations (CFD) the effects of the supply and extract air terminals on contaminants distribution in offices equipped with a cooled ceiling has been investigated. Besides, in order to fully characterize the indoor climate of residential rooms or offices, an extensive experimental study has been carried out in a test room to determine both thermal comfort and ventilation effectiveness for different solutions of mixing ventilation and displacement ventilation combined with floor radiant systems. In particular, the effects of supply and extract air terminals positions by using low air change rates in mixing ventilation and the effects of different ventilation rates with displacement ventilations terminals have been analyzed. Results from experiments have been used for the validation of a CFD model for the prediction of air distribution in rooms equipped with mixed or displacement ventilation, combined with heating/cooling floor systems.
In questo lavoro di dottorato vengono presentati i risultati di uno studio sui sistemi radianti per il raffrescamento ed il riscaldamento in ambito civile e sulla loro integrazione con opportuni sistemi di ventilazione meccanica. Le prestazioni energetiche in regime stazionario e transitorio, così come le prestazioni di comfort termico e di qualità dell’aria garantita, sono state studiate mediante l’ausilio di prove sperimentali, di simulazioni fluidodinamiche e di altri codici di calcolo. Gli studi sperimentali sono stati realizzati in parte in Italia, presso i laboratori dell’azienda RHOSS S.p.A di Codroipo (Udine), e in parte presso i laboratori dell’ICIEE (International Centre for Indoor Environment and Energy), dell’Università Tecnica di Danimarca, (DTU) a Lyngby (DK). L’aspetto più rilevante di questo lavoro è legato alla sempre maggiore diffusione dei sistemi radianti come soluzione per il riscaldamento ed il raffrescamento di ambienti interni, in quanto combinano vantaggi energetici ad elevati livelli di comfort termico. Per ragioni dovute alla piccola differenza di temperatura tra l’ambiente e il fluido termovettore, i sistemi radianti si interfacciano molto bene con caldaie a condensazione, pompe di calore, sistemi free cooling, collettori solari e altre sorgenti rinnovabili e soluzioni ad alta efficienza energetica. Il calcolo della resa termica di tali sistemi viene eseguito mediante le equazioni valide per la convezione in regime stazionario, come quelle fornite dalle norme Europee EN 1264 ed EN 15377. In letteratura esistono numerose correlazioni valide per il calcolo della potenza convettiva di superfici orizzontali e verticali e di superfici interne di stanze reali; le norme EN 1264 ed EN 15377 consigliano correlazioni diverse e lo stesso accade per codici si simulazione energetica degli edifici. Ad oggi non è disponibile una chiara definizione di coefficiente di scambio termico convettivo per i sistemi radianti, specialmente per quanto riguarda pavimenti freddi e soffitti caldi. Il primo obiettivo di questa tesi è stato di realizzare un’analisi critica delle correlazioni disponibili in letteratura adatte ai sistemi radianti e di proporre delle equazioni per ogni configurazione di riscaldamento o raffrescamento da soffitto, pavimento o parete. In ambito residenziale il pavimento radiante rappresenta una delle soluzioni più richieste grazie all’elevato livello di comfort termico garantito; tuttavia, al fine di migliorare la qualità dell’aria e specialmente a causa della necessità di deumidificare l’aria in estate per evitare formazione di condensa, accanto al sistema radiante andrebbe installato un sistema di ventilazione meccanica. L’aria primaria in estate è solitamente a temperatura più bassa della temperatura della stanza e dotata di una certa velocità; nel caso di immissione da bocchette installate vicino ad una superficie radiante, lo scambio convettivo potrebbe venire variato rispetto ad una soluzione senza ventilazione. Mediante uno studio con simulazioni fluidodinamiche CFD è stato possibile valutare l’incremento dello scambio convettivo da un soffitto freddo mediante lo sfruttamento di aria primaria. I sistemi radianti, in particolare i sistemi a soffitto, rappresentano un’ottima soluzione per rimuovere i carichi termici degli uffici durante il periodo estivo, ma allo stesso tempo possono essere usati per il riscaldamento invernale degli stessi con buone prestazioni energetiche e di comfort termico. La differenza sostanziale è che durante la stagione invernale il sistema radiante si trova a lavorare prevalentemente in regime stazionario, mentre durante la stagione estiva i carichi esterni dovuti alla radiazione solare e all’escursione diurna, accompagnati da carichi interni dovuti all’occupazione umana, determinano condizioni piuttosto variabili durante la giornata. Il comportamento di sistemi radianti a regimi stazionari e transitori sono state studiate mediante prove in camera climatica; inoltre un modello di calcolo chiamato Digithon, sviluppato all’interno del Dipartimento di Fisica Tecnica dell’Università di Padova, è stato validato mediante un confronto con dati sperimentali. Seguendo un’opportuna procedura, riportata nella tesi, è stato possibile impostare dei profili di carico che simulano una tipica giornata estiva o invernale su una parete della stanza ed è stato studiato come il soffitto radiante reagisca per cercare di mantenere una certa temperatura di comfort nella stanza. Al fine di mantenere una buona qualità dell’aria, evitare la formazione di condensa, ma anche per incrementare la capacità di raffrescamento quando richiesto, i sistemi radianti per gli uffici andrebbero sempre associati a sistemi di ventilazione meccanica. Accanto ai tradizionali sistemi a soffitto con ventilazione a miscelazione, le soluzioni con ventilazione a dislocamento accoppiate a sistemi a pavimento o a soffitto sono alternative di crescente interesse per gli uffici. In edifici dove sia bassa la quantità di inquinanti emessi dai materiali edili, dai mobili e dalle attrezzature, la quantità di bioeffluenti dagli occupanti, dei quali l’anidride carbonica CO2 è normalmente usata come principale indicatore, è determinante per la qualità dell’aria interna. La capacità di rimozione dei contaminanti e, parallelamente, la capacità di immettere aria pulita negli ambienti sono espresse dall’efficienza di ventilazione (ventilation effectiveness). Mediante simulazione fluidodinamiche CFD è stato possibile confrontare l’efficienza di rimozione dei contaminanti utilizzando diverse soluzioni di ventilazione a dislocamento piuttosto che soluzioni tradizionali a miscelazione. La qualità di un ambiente interno andrebbe misurata in termini sia di comfort termico garantito all’occupante che di qualità dell’aria. Attraverso prove sperimentali in laboratorio, i principali indici di comfort termico e di efficienza di ventilazione sono stati determinati per diverse configurazioni di ventilazione a miscelazione e di ventilazione a dislocamento in ambienti rappresentativi di applicazioni residenziali o del terziario. I risultati sono stati in seguito utilizzati per effettuare una validazione di un modello fluidodinamico (CFD) creato per la previsione del movimento dell’aria in ambienti residenziali o uffici.

sempre più il concetto di qyalità prodotto è centrale nelle realtà manifatturiere per almeno due aspetti: da un lato il saving di carattere economico; dall'altro la possibilità di perseguire comportamenti ecocompatibili L'elaborato analizza le strade ed i percorsi attraverso cui un sistema fabbrica può intraprendere percorsi di miglioramento continuo volti al perseguimento di questi due obiettivi

Durant ces dernières années la qualité a beaucoup évolué. Elle est passée d'une qualité contrôlée à une qualité totale. Cette évolution oblige les entreprises à rechercher de nouvelles. Les travaux réalisés dans ce mémoire de thèse ont pour objectif de contribuer efficacement à l'amélioration des méthodes et techniques pour maitriser la qualité des produits. Ces travaux, pluridisciplinaires, couvrent des domaines aussi différents que l'informatique, l'organisation et la statistique. Ce mémoire de thèse a été structuré en trois contributions distinctes : - une intégration des données issues du processus de contrôle qualité dans un système d'information unifié. - une réalisation d'un modèle qualimétrique pour évaluer la mise en place d'un modèle normatif d'assurance qualité. - une analyse critique des conditions d'utilisation des plans d'expériences pour optimiser les procédés.

Cette étude est motivée par le besoin industriel d'améliorer la fiabilité du contrôle visuel de la qualité. Elle valide les grands principes à prendre en considération, lors de la mise en œuvre de systèmes automatisés de vision industrielle. La réalisation d'une telle chaîne de traitement requiert des techniques de recherche allant de l'électronique à l'intelligence artificielle, en passant par la physique et le traitement de l'image Le cahier des charges de ces systèmes doit être formalisé, afin d'être transporté termes de solution informatisée. Les conditions d'éclairage de la scène à contrôler, sont définies en fonction des paramètres physiques de l'application, afin d'obtenir une image numérique facilement exploitable. Les traitements de l'image, ainsi obtenus, sont déterminés en respectant des critères de rapidité et de robustesse. Tous les traitements retenus sont réunis dans un logiciel interactif, spécialement développé lors de cette étude. Les composants de base d'un système de vision sont classifiés en fonction de leurs caractéristiques techniques, puis deux exemples d'application sont détaillés : - détection de défauts dans des circuits imprimés, - caractérisation de matériaux composites. La conclusion fait le point de la situation et insiste essentiellement sur l'évolution technique future qui permettra d’agrandir le cercle des applications lié à l'utilisation de méthodes de simulation de la perception humaine.

Dans cette thèse, nous abordons deux thématiques très différentes du génie industriel, mises en oeuvre sur un même cas d'application industriel. Tout d'abord, nous nous intéressons à l'analyse des systèmes industriels en intégrant deux courants de pensée : la modélisation d'entreprise d'une part, et l'amélioration des systèmes industriels d'autre part. Nous proposons une grille d'analyse/action basée sur la modélisation d'entreprise et permettant de mettre en évidence les dysfonctionnements du système industriel et les instruments d'amélioration à mettre en oeuvre. Un cas d'application est développé sur notre problématique industrielle. Ensuite, un problème d'ordonnancement original est issu du précédent cas d'application. Il s'agit d'un atelier à machines parallèles flexibles et nécessitant des ressources secondaires (outils et intervention d'opérateurs), avec temps de préparation importants, mais sans contrainte de précédence entre les opérations d'un job. Nous étudions le critère de la somme des retards des jobs. Deux approches sont proposées pour ce problème : par heuristique et par recuit simulé. Pour l'approche heuristique, une règle appelée ATCTRS est développée. Elle cherche à réaliser un compromis entre le retard d'une opération et la bonne occupation de la machine. Pour l'approche par méta-heuristique, nous étudions principalement une structure de voisinage adaptée au problème à résoudre.

As the philosophy of doing business shift from sell what you can produce to produce what you can sell so do the customers’ specification continuously become a vital tool during product development process, hence increasing the volatility of the business environment. The objective of this thesis is to thoroughly review literature to be supported by cases why most companies fail in sustaining improvement programs then map out a pathway that will leads to successful implementation.

A series of reasons were found which impedes the successful implementation of improvement programs which includes; management is unable to define the problem to be solve and the method of measurement, implementers choose wrong parameters for improvement, implementers sub-optimize or may not involve everyone that will be affected by the program, top management gives little or no attention to improvement programs and at times they may even loose focus, so many concurrent improvement programs are executed which will result to resource overloading, teams members most often lack data integrity, and teams members are often scared to try new ideas hence prohibiting the chances of innovation. To minimize this cankerworm, a number of steps has been mentioned. The steps were divided into two phases, the selection phase and the implementation. The selection process includes; defining the program, focus program on improving shareholders’ value and choose program base on a holistic perspective. The implementation phase includes; commitment of top management, prioritize projects, use critical chain project management to plan and execute project, lay emphasis on quality data, minimize the number of concurrent projects, encourage risk taking, and spend time and resources on value adding activities.

Context This thesis verifies a method developed on alignment issues in different data points and is useful to validate the method in those data points. To find the alignment/misalignment problems occurring within the stakeholders in a company is done through surveys using Hierarchical Cumulative Voting (HCV). This paper presents a case study to explain the importance of alignment between the stakeholders to achieve quality. Time, scope and cost are given higher priority leaving quality as it is hard to measure. To maintain quality in a software product is a major challenge in most of the software organizations. Stakeholders play a major role in software development. Without the alignment and common understanding between the stakeholders, it is highly difficult to achieve successful software project with good quality. The reasons for misalignment/alignment between the stakeholders are being explained clearly in this thesis based on the interviews and the survey conducted in software development companies under the novelty of case study. Objectives To evaluate the usefulness of alignment approach in different data points, to achieve product quality, for understanding the reasons for misalignment and to provide common approach for aligning we need to know the actual aligning priorities given by the stakeholders. We have one method for aligning and we want to see how actual alignment is different in different data points. To find the reasons for different stakeholders’ groups focusing on different quality attributes and to manage quality that helps in aligning quality requirements in future. Methods In order to know the importance of quality, prioritization of requirements and about the alignment problem we have conducted the literature review. To understand the problem and to know the reasons for misalignment in the companies we have conducted a case study in which we interviewed 8 employees from a company and to know the individual ranking of quality attributes we also made use of surveys in which 17 individuals from two companies had participated. Results We have identified the reasons for misalignment using interviews in one company and the individual priorities given to different quality attributes through surveys in two different companies. The qualities are prioritized by the stakeholder groups in the surveys and these are used to calculate the alignment/misalignment between the groups using spearman rank correlation which pointed that there are some disagreements between the stakeholder groups. Conclusions This paper explains the results obtained from a case study for determining the alignment/misalignment between different stakeholder groups and the reasons for this situation. Through surveys we found that there is a strong disagreement between the stakeholders in one company and partial agreement in the other company with respect to priorities they assign to individual qualities and the reasons behind this are obtained through interviews. The reasons for misalignment are lack of common understandings between the stakeholders, less discussion on quality requirement, undocumented priorities, no importance given to quality and others.
This Thesis work is about Software Product Quality and how it is achieved through alignment between the people in understanding the requirements.
0763138272, 0739849383

Quality control of wastewater is an important treatment process more so now, tnan ever before. Due to an extremely unpredictable nature of the wastewater, which is a mixture of both inorganic and organic waste, it is very difficult to neutralise. Two approaches have been proposed in developing alternative control strategies as suggestions for the pH control of the wastewater in an industrial plant. The first is to develop a mathematical model of a continuously stirred tank reactor (CSTR) with a possible use of MATLAB®. Three different control methods (linear, nonlinear and adaptive) are subject to vigorous theoretical testing and are proposed as a possible solution. The second, a parallel approach, has been to build a laboratory scale experimental reactor using a seven litre continuously stirred tank with monitors for influent flow, influent pH and reactor tank pH. Results suggest that a more sophisticated controller than the simple PID control, currently in operation, could lend Itself to overcoming the problem of persistent large spikes in the pH of the influent. Further work would consider the implementation of these results to the actual industrial wastewater treatment plant.

Measuring the Environmental Performance of industry is an essential element in the movement to minimise the impact that industry has on the environment. There has been a significant increase in interest in this area over the last few years, however it is recognised that the available literature still tends towards the conceptual and theoretical and there is little practical advice for a business wishing to undertake environmental performance measurement. This project has concentrated on the practical development of tools and techniques for measuring environmental performance in a large, complex engineering company, using LucasVarity as an example. The portfolio discusses the general trends and approaches in environmental performance measurement, explains the specific aspects developed in practice and their results. Finally, the general conclusions for industry are discussed.

Software architecture has been identified as an increasingly important part of software development. The software architecture helps the developer of a software system to define the internal structure of the system. Several methods for evaluating software architectures have been proposed in order to assist the developer in creating a software architecture that will have a potential to fulfil the requirements on the system. Many of the evaluation methods focus on evaluation of a single quality attribute. However, in an industrial system there are normally requirements on several quality aspects of the system. Therefore, an architecture evaluation method that addresses multiple quality attributes, e.g., performance, maintainability, testability, and portability, would be more beneficial. This thesis presents research towards a method for evaluation of multiple quality attributes using one software architecture evaluation method. A prototype-based evaluation method is proposed that enables evaluation of multiple quality attributes using components of a system and an approximation of its intended runtime environment. The method is applied in an industrial case study where communication components in a distributed realtime system are evaluated. The evaluation addresses performance, maintainability, and portability for three alternative components using a single set of software architecture models and a prototype framework. The prototype framework enables the evaluation of different components and component configurations in the software architecture while collecting data in an objective way. Finally, this thesis presents initial work towards incorporating evaluation of testability into the method. This is done through an investigation of how testability is interpreted by different organizational roles in a software developing organization and which measures of source code that they consider affecting testability.

In quality control applications, the most basic tasks are monitoring and fault diagnosis. Monitoring results determines if diagnosis is required, and conversely, diagnostic results aids better monitoring design. Quality monitoring and fault diagnosis are closely related but also have significant difference. Essentially. monitoring focus on online changepoint detection, whilst the primary objective of diagnosis is to identify fault root causes as an offline method. Several critical problems arise in the research of quality control: firstly, whether process monitoring is able to distinguish systematic or assignable faults and occasional deviation; secondly, how to diagnose faults with coupled root causes in complex manufacturing systems; thirdly, if the changepoint and root causes of faults can be diagnosed simultaneously. In Chapter 2, we propose a novel Bayesian statistical process control method for count data in the presence of outliers. That is, we discuss how to discern out of control status and temporary abnormal process behaviors in practice, which is incapable for current SPC methodologies. In this work, process states are modeled as latent variables and inferred by the sequential Monte Carlo method. The idea of Rao-Blackwellization is employed in the approach to control detection error and computational cost. Another contribution of this work is that our method possesses self-starting characteristics, which makes the method a more robust SPC tool for discrete data. Sensitivity analysis on monitoring parameter settings is also implemented to provide practical guidelines. In Chapter 3, we study the diagnosis of dimensional faults in manufacturing. A novel Bayesian variable selection oriented diagnostic framework is proposed. Dimensional fault sources are not explicitly measurable; instead, they are connected with dimensional measurements by a generalized linear mixed effect model, based on which we further construct a hierarchical quality-fault model to conduct Bayesian inference. A reversible jump Markov Chain Monte Carlo algorithm is developed to estimate the approximate posterior probability of fault patterns. Such diagnostic procedure is superior over previous studies since no numeric regularization is required for decision making. The proposed Bayesian diagnosis can further lean towards sparse fault patterns by choosing suitable priors, in order to handle the challenge from the diagnosability of faults. Our work considers the diagnosability in building dimensional diagnostic methodologies. We explain that the diagnostic result is trustworthy for most manufacturing systems in practice. The convergence analysis is also implemented, considering the trans-dimensional nature of the diagnostic method. In Chapter 4 of the thesis, we consider the diagnosis of multivariate linear profile models. We assume liner profiles as piece-wise constant. We propose an integrated Bayesian diagnostic method to answer two problems: firstly, whether and when the process is shifted, and secondly, in which pattern the shift occurs. The method can be applied for both Phase I and Phase II needs. For Phase I diagnosis, the method is implemented with no knowledge of in control profiles, whereas in Phase II diagnosis, the method only requires partial observations. To identify exactly which profile components deviate from nominal value, the variability of the value of profile components is marginalized out through a fully Bayesian approach. To address computational difficulty, we implement Monte Carlo Method to alternatively inspect between spaces of changepoint positions and fault patterns. The diagnostic method is capable to be applied under multiple scenarios.

Job performance aids (JPAs) have been studied for many decades in a variety of disciplines and for many different types of tasks, yet this is the first known research experiment using JPAs in a quality assurance (QA) context. The objective of this thesis was to assess whether a JPA has an effect on the performance of a QA observer performing the concurrent dual verification technique for a basic assembly task. The JPA used in this study was a simple checklist, and the design borrows heavily from prior research on task analysis and other human factors principles. The assembly task and QA construct of concurrent dual verification are consistent with those of a high consequence manufacturing environment. Results showed that the JPA had only a limited effect on QA performance in the context of this experiment. However, there were three important and unexpected findings that may draw interest from a variety of practitioners. First, a novel testing methodology sensitive enough to measure the effects of a JPA on performance was created. Second, the discovery that there are different probabilities of detection for different types of error in a QA context may be the most far-reaching results. Third, these results highlight the limitations of concurrent dual verification as a control against defects. It is hoped that both the methodology and results of this study are an effective baseline from which to launch future research activities.

Melting of frozen water in food products is denoted thawing. The phase change requires energy, and takes place at a constant temperature for pure water. For mixtures of water, fat, protein and ashes (i.e. foodstuffs) this phase change will take place at a gliding temperature. Thawing is physically the opposite process to that of freezing. The heat flow is reversed and instead of extracting heat from the product, heat is directed into it. Although opposite processes, thawing is more difficult to carry out with respect to predictability and controllability. This is due mainly to three aspects:

1. Increased heat flow resistance as the thawing proceeds.

2. Reduced temperature difference (ΔT) between product and media.

3. More difficult to monitor the process and product end temperature accurat

The food processing industry depends on a continuously and safe supply of raw material, in order to utilise process equipment better, improve production planning and to create stable and secure working environment for the employees. The fish industry is very important for Norway, and its export value (NOK 30,6 billion in 2001¹) is the second highest after oil and higher than gas. The fact that supply of fresh raw material (i.e. fish) often is dependent on seasonal variations, weather conditions, quotes and regulations (governmental and international), has been a great intensive to use frozen raw material in the fish process industry.

A survey amongst 155 fish processing plants throughout Norway showed that 75 % of them used thawing in their production and further 23% claimed that they would do so in the future. 93 % of the companies that thawed did so in an uncontrolled manner. The challenges in industrial thawing are many:

• Block frozen products changes size during thawing and are generally more difficult to handle

• The product texture are temperature dependent

• Size variations – both single fish and batches

• Use of both fresh and frozen raw material

• Company culture

Thawing by heat transfer through the surface has been studied for three different products; Salmon, Cod and Mackerel. A slightly different approach has been used for these products depending on the raw material availability, industrial needs and relevance.

The purpose of this analytical study is to determine the degree of application of Total Quality Management (TQM) philosophy and practices in the industrial corporations in Jordan. Through detailed examination of primary and secondary empirical data from these corporations, the study examines the link between TQM and labour productivity. The population of the study consists of all Jordanian shareholding corporations listed under the industrial category in Amman Stock Exchange. In late 1998, this consisted of a total of 90 companies. Both quantitative and qualitative data were collected and analysed in investigating the relationship between TQM implementation and labour productivity. Detailed survey responses from 76 participating companies were classified into two groups: high-level TQM implementation and low-level TQM implementation. About 60% of these companies were classified as companies with high-level TQM. Descriptive analysis of the survey responses plus company report data found that mean labour productivity measurements for companies with high-level TQM were significantly higher than for those with low-level TQM over the years (1993-1998). Also mean growth rates of labour productivity measurements for companies with high-level TQM were higher than for those with low-level of TQM during this period. Regression analysis demonstrated a statistically significant positive relationship between TQM and labour productivity. This relationship showed a high positive slope in companies with ISO 9000 certification, and considerably lower (but still positive) slope in companies without ISO 9000 certification.
Doctor of Philosophy (PhD)

Daylight simulators are widely used in industries for visual assessments and internal light sources of colour measuring instruments. As the CIE defined its standard daylight illuminants based on a combination of various measurement results, the precise realisation of CIE daylight illuminants is virtually impossible. Daylight simulators have therefore been developed to simulate the CIE daylight illuminants only approximately. The variety of daylight simulators used in practice caused a big concern on the quality of daylight simulators for industrial colour quality control. This study aims to investigate the variations of practical daylight simulators and the performances of standard methods including the BS950 band value method, CIE metamerism index method and CIE colour rendering index method for evaluating daylight simulators. The study also aims to reveal the discrepancies between various standards for specifying daylight simulators and to highlight the influence of these discrepancies on industrial colour quality control. An industrial survey on viewing cabinets was first carried out. The variations of D65 and D50 simulators accumulated were analysed in terms of colorimetric and spectral results. The results show that the D65 simulators generally performed better than the D50 simulators with higher CIE metamerism index and colour rendering ratings. The filtered tungsten lamps exhibit the best quality while the three-band fluorescent lamps show the worst quality. It was also found that both the CIE and ISO might not give appropriate specifications for the chromaticities of daylight simulators, i. e. too lenient for the former and too strict for the latter. A psychophysical experiment using real metameric pairs was conducted for evaluating the quality of six D65 daylight simulators. It was found that in general, all the simulators studied agreed well with each other in terms of the visual results, except for the three-band fluorescent lamp. The results show that BS 950 band value method and CIE metamerism index method are equally reliable for evaluating the quality of daylight simulators. It was also revealed that a simulator having band-value deviations well below the BS 950 tolerance corresponds to a high CIE metamerism index rating and therefore is judged as good qualitySeven metamer sets were generated based on different principles. These metamer sets were used to compare various metamerism indices for quantifying metamerism as well as to evaluate two methods, goodness-of-fit of SPD and CIE metamerism index for assessing daylight simulators. The results show that the measure of goodness-of-fit of SPD does not agree well with the CIE metamerism index method. It was proved that the CIE metamers are representatives of real metamers, however, the CIE metamer set gives smaller colour differences for the test simulators because it exhibits lower metamerism degree comparing to the generated metamer sets. It was also found that a limited number of metamers could be selected from a range of real metamers to perform as effective as the CIE set for evaluating daylight simulators. The CIE colour rendering index method for evaluating daylight simulators was investigated using the CIE test colours and new sets of test colours. It was found that the CIE test colour sets agreed better with the paint sample sets than with the textile or thread sample sets. The four colour difference formulae, CIELAB, CMC, CIE94 and CIEDE2000, exhibit a similar performance for 'calculating CIE colour rendering index, and they all outperform CIEU*V*W*. No significant difference was found for the performance between two chromatic adaptation transforms, von Kries and CMCCAT2000. The results also show that it might be more appropriate to adopt the total CIE test colours instead of the first eight colours for calculating CIE colour rendering index. A new set of test colours, selected from the CIE'and other test colours for showing medium to large colour inconstancy as well as covering a large colour gamut, was proved to have a better performance than the CIE test colours. " `" Finally, a method was developed for optimisingthe spectral power distributions of daylight sithulators. Significant improvements' inquality were' achieved for the test lamps after the optimisation. A guideline for viewing cabinet design was also proposed based on the relevant standards and information accumulated from the industrial survey on viewing cabinets

Investigating internal employee behaviors that influence firm results is an area of on-going interest to both academics and practitioners. This study combined the two recently developed constructs of internal market orientation and industrial service quality to investigate their relationship. The integration of the business outcomes of overall service quality, customer satisfaction, and commitment to the relationship were included to add practical application to study. Additionally, the moderator length of relationship between service provider and customer was included to examine its influence in the model. Internal marketing and market orientation influenced the development of the internal market orientation. Decades of studies into service quality lead to the development of the business-to-business service quality scales applied to this study. Studying these constructs in real world settings, including the moderator, and measuring subjective business outcomes was conducted to confirm scale use, broaden the settings, and offer depth to the field of study. Two surveys to employees and one survey to matching customers created 107 dyad records for structural equation model analysis. Results showed no significant relationship between internal market orientation and industrial service quality. There was a significant relationship between industrial service quality and overall service quality perception, confirming past studies. However, counter to past research industrial service quality did not influence customer satisfaction and commitment to the relationship. A surprising result was the significant relationship reported between employee perceived service quality and the two business outcomes of customer satisfaction and commitment. This research did not support the theoretical premise that internal market orientation is an antecedent to industrial service quality. This study reported mixed results for the connections between perceived service quality and the business outcomes included. Some of the limitations from previous research were addressed while a more integrated model was investigated to add to the understanding of the marketing concept.

Le développement de matériaux biosourcés possédant un large éventail de propriétés est devenu une préoccupation majeure dans notre société actuelle, pour tendre vers une bioéconomie durable. Dans ce contexte, les nanofibrilles de cellulose (CNF) sont très prometteuses, de par leurs propriétés mécaniques, optiques, rhéologiques et barrières intéressantes. En revanche, plusieurs verrous technologiques freinent encore la rentabilité de leur production à l’échelle industrielle, tels que les problèmes de procédé ou de toxicité liés aux prétraitements de la cellulose, et la forte consommation énergétique des procédés de fibrillation mécanique. Ce projet vise au développement de prétraitements innovants et à l’optimisation de plusieurs procédés de fibrillation mécanique, avec pour objectif de produire à l’échelle industrielle des CNF de haute qualité. Dans un premier temps, trois prétraitements ont été étudiés, impliquant un traitement alcalin et enzymatique couplé, l’adsorption d’un polyélectrolyte, et l’hydrolyse enzymatique in situ à fort taux de matière sèche pendant la fibrillation par extrusion bi-vis. Ensuite, un procédé de raffinage à disque a été optimisé pour la production de CNF, en vue de l’implémentation de ces prétraitements à l’échelle pilote. Plusieurs essais industriels avec une ligne de raffinage spécifique au papier calque ont souligné la pertinence de ce procédé pour la production de CNF en grande quantité, menant à une réduction significative de la consommation énergétique comparée à des procédés conventionnels. Enfin, le raffinage à disque a été combiné respectivement avec l’extrusion bi-vis, le broyage ultra-fin et l’homogénéisation. Cette stratégie a permis de dépasser la limitation de la qualité de CNF rencontrée avec l’utilisation du raffinage seul. Les résultats de ce projet contribuent à la connaissance des prétraitements et procédés pour la production de CNF, et sont un pas vers leur production efficace à l’échelle industrielle
The development of biobased materials with a wide range of properties has become a key issue in today’s society, to move towards a durable bioeconomy. In this context, cellulose nanofibrils (CNF) are very promising, due to their interesting mechanical, optical, rheological and barrier properties. However, several technological challenges still restrain their cost-efficient production at the industrial scale, such as the process or toxicity issues of the cellulose pretreatments, and the high energy consumption of the mechanical fibrillation processes. This project aims at developing innovative pretreatments and optimize several mechanical fibrillation processes, with an objective of producing high quality CNF at the industrial scale. First, three pretreatments were studied, involving a coupled alkaline and enzymatic treatment, the adsorption of a polyelectrolyte, and in situ enzymatic hydrolysis at high solid content during fibrillation by twin-screw extrusion. Then, a disk refining process was optimized for CNF production, for the implementation of these pretreatments at the pilot scale. Several industrial trials with a specific tracing paper refining line also underlined the relevance of this process for large scale CNF production, leading to a significant decrease of energy consumption compared to conventional processes. Finally, disk refining was combined with twin-screw extrusion, ultra-fine grinding and homogenization, respectively. This strategy enabled to overcome the limitation of CNF quality encountered with the use of refining alone. The results of this project contribute to the knowledge on pretreatments and processes for CNF production, and are a step towards their efficient production at industrial scale

The purpose of this analytical study is to determine the degree of application of Total Quality Management (TQM) philosophy and practices in the industrial corporations in Jordan. Through detailed examination of primary and secondary empirical data from these corporations, the study examines the link between TQM and labour productivity. The population of the study consists of all Jordanian shareholding corporations listed under the industrial category in Amman Stock Exchange. In late 1998, this consisted of a total of 90 companies. Both quantitative and qualitative data were collected and analysed in investigating the relationship between TQM implementation and labour productivity. Detailed survey responses from 76 participating companies were classified into two groups: high-level TQM implementation and low-level TQM implementation. About 60% of these companies were classified as companies with high-level TQM. Descriptive analysis of the survey responses plus company report data found that mean labour productivity measurements for companies with high-level TQM were significantly higher than for those with low-level TQM over the years (1993-1998). Also mean growth rates of labour productivity measurements for companies with high-level TQM were higher than for those with low-level of TQM during this period. Regression analysis demonstrated a statistically significant positive relationship between TQM and labour productivity. This relationship showed a high positive slope in companies with ISO 9000 certification, and considerably lower (but still positive) slope in companies without ISO 9000 certification. ACCESS RESTRICTED TO ABSTRACT ONLY.

Nowadays, Computer Vision comprises a lot of different useful applications, ranging from real-time surveillance to series production. Since most of the mass-production systems are automatized, there is a non-zero probability for an error to happen, which in some cases would make the final product useless. In that regard, many factories often integrate into their assembly line a specialized camera system for the purpose of identifying errors at the end or during the production. In particular, a device composed of a network of calibrated cameras is usually employed to identify metrological and visual defects. Together with cameras, such device could comprise multiple light sources to easily spot defects caused by an imperfect structure of the object's surface. This work explores the possibility of increasing the precision of such an inspection system by estimating the position of each light source. The estimation is carried out through the analysis of the shading observed on the surface of some spherical Lambertian objects in different poses and from different points of view.

Fertilizer production is a massive global industry with the global consumption of the three main fertilizer nutrients, nitrogen, phosphate and potassium estimated at 187 million tonnes in 2016 with an anticipated annual growth of approximately 2% for the foreseeable future. In 2016 the global fertilizer market was estimated to have an overall market value of 141 billion US dollars. Fertilizer production produces significant liquid waste as process water used for the various separations, cleaning, emulsifying and dilution processes absorbs various nutrients and contaminants from these production processes. This liquid waste has characteristically high concentrations of nutrients derived from the base fertilizer, such as various dissolved phosphate compounds for phosphate-based fertilizer production or dissolved nitrogenous compounds for nitrogen based fertilizer production. These contaminants are inherently nutrients that could be recovered for beneficial re-use. The phosphate and potassium minerals used in fertilizer production are obtained from ores mined from the earth, thus the re-use of these mineral present particular significance when taking into accounting the declining global supply of these ores. Furthermore, if these liquid wastes are not disposed of correctly they can lead to detrimental environmental impacts such as eutrophication and ecological degradation in water courses. This study addresses this problem by presenting three novel treatment techniques to treat the liquid waste produced from a fertilizer production plant. A liquid waste sample obtained from a particular fertilizer production plant producing primarily nitrogen-based fertilizer is used as a design basis to evaluate the three presented treatment techniques. The techniques are evaluated based on their economic feasibility, technical feasibility and resource recovery ability. The three treatment techniques studied were the Sharon-Anammox bioreaction process, electrodialysis with struvite recovery process and combined forward-reverse osmosis process. The technical feasibility of the processes was primarily evaluated based on the effluent water quality from the treatment systems. The effluent quality index (EQI) was used as a comparative measure of the effluent quality of the processes. All three processes were found to perform inadequately from a technical feasibility perspective as demonstrated by the negative EQI values obtained for the processes. The Sharon-Anammox bioreaction process was found to perform poorly because its application is limited to treatment of waste streams containing high ammonia concentrations such as in conventional domestic waste. Therefore, the Sharon-Anammox process was not suited to the fertilizer effluent which also contained high nitrates, phosphates and total dissolved solids. The electrodialysis process performed poorly as it was unable to effectively remove the ammonium cations from the process water. The combined forward-reverse osmosis process performed poorly because a resource recovery step was not included to treat the concentrated waste stream discharged from the forward osmosis step of the process. It was identified that a similar struvite recovery step should be added to the combined forward-reverse osmosis process to improve the technical feasibility of the process and to provide the process with resource recovery capabilities. From an economic feasibility perspective, it was found that the addition of the struvite recovery setup to the electrodialysis process increased the capital costs of the process to between 300% and 500% of the other two options. However, with the omission of the struvite recovery setup the capital costs of all three processes were in a similar range.