Η ανάπτυξη βιομηχανικών οικοσυστημάτων αποτελεί τη βασική κατεύθυνση της βιομηχανικής οικολογίας, η οποία προβάλλει ως ένα από τα πλέον ολοκληρωμένα μοντέλα αειφόρου ανάπτυξης. Η διδακτορική διατριβή αφορά στις συστημικές παρεμβάσεις που απαιτούνται για τη δημιουργία, συντήρηση και ανάπτυξη βιομηχανικών οικοσυστημάτων ή τεχνολογικών θυλάκων όπως ορίζονται υπό το πρίσμα της κοινωνικοτεχνικής προσέγγισης. Προς αυτήν την κατεύθυνση, η εργασία αποτελεί μια καινοτόμο προσπάθεια, η οποία εστιάζει (σε μίκρο και μάκρο επίπεδο) στα προβλήματα που εμφανίζονται και στις παρεμβάσεις που απαιτούνται κατά τη μετάβαση προς ένα νέο οικοβιομηχανικό τεχνολογικό καθεστώς. H διατριβή στοχεύει κυρίως στη παραγωγή θεωρίας και καθοδηγητικών πλαισίων σχετικά με τη διαδικασία μετάβασης προς το οικοβιομηχανικό παράδειγμα μέσω δευτερογενούς ανάλυσης υφιστάμενων περιπτώσεων και εφαρμογής θεωρητικών εργαλείων από τα πεδία της συστημικής επιστήμης και των σπουδών τεχνολογίας και επιστήμης. Αρχικά, το βιομηχανικό οικοσύστημα αντιμετωπίζεται ως σύστημα, δηλαδή ως σύνολο μερών τα οποία παρουσιάζουν αναδυόμενες ιδιότητες, και αναλύεται με τη βοήθεια θεμελιωδών συστημικών χαρακτηριστικών. Στη συνέχεια, το βιομηχανικό οικοσύστημα αντιμετωπίζεται ως οργάνωση, δηλαδή ως μια συγκροτημένη ομάδα εμπλεκομένων που στοχεύουν στην πραγμάτωση συγκεκριμένων στόχων, και αναλύονται τα προβλήματα που ανακύπτουν κατά το σχεδιασμό και την υλοποίηση των απαιτούμενων παρεμβάσεων. Τέλος, σε μια συνθετική οπτική, το βιομηχανικό οικοσύστημα αντιμετωπίζεται ως ένα νέο τεχνολογικό καθεστώς, δηλαδή ως ένα σύνολο πεποιθήσεων, κανόνων και τεχνολογιών που ρυθμίζει και διαμορφώνει τη βιομηχανική δραστηριότητα, και εξετάζεται η μετάβαση προς ένα οικοβιομηχανικό σύστημα παραγωγής, υπό το πρίσμα της κοινωνικοτεχνικής προσέγγισης, μέσω συστημικών παρεμβάσεων σε σχετικούς τεχνολογικούς θύλακες. Στη διατριβή προτείνονται ερμηνευτικά και καθοδηγητικά πλαίσια, τα οποία σε μίκρο επίπεδο μπορούν να εφαρμοσθούν στη διαχείριση και ανάπτυξη υφιστάμενων βιομηχανικών οικοσυστημάτων, ενώ σε μάκρο επίπεδο, μπορούν να χρησιμοποιηθούν στη χάραξη στρατηγικών πολιτικών οικοβιομηχανικής ανάπτυξης. / This thesis concerns the systemic interventions required for the development, maintenance and diffusion of industrial ecosystems managed as technological niches under the prism of the socio-technical approach. Towards this end, it is an innovative effort that concentrates on the issues emerged and on the interventions required in the transistion towards a novel eco-industrial technological regime. The main contribution of the research reported is the development οf theoretical constructs, as well as a normative framework for the transition process towards an eco-industrial paradigm. Methodologically, the analysis was based on a secondary research approach and application of theoretical tools from the disciplines of Systems Science and Science and Technology Studies. Initially, the industrial ecosystem was considered as a system and was analysed through fundamental systems concepts. Following, it was approached as an organization, and the associated problems of its transition process were analyzed. Finally, towards a more synthetic view, industrial ecosystems were considered as the constituent parts of a novel socio-technical regime of productions systems. The transition towards such an eco-industrial regime was analyzed through systemic interventions in technological niches by reference to existing industrial ecosystems. The thesis proposes explanatory and prescriptive frameworks for the design of the necessary interventions. At a micro level, the frameworks developed can be applied to the management and further development of existing industrial ecosystems, while at a macro level, they can be used by policy makers in the development of strategies aiming at the diffusion of the eco-industrial paradigm.

Current federal and provincial efficiency standards for residential water heating are based solely on the tested efficiency of individual water heating devices. Additional energy expended or saved as the water cycles through the home is not taken into account. This research, co-funded by British Columbia’s Ministry of Energy, Mines and Petroleum Resources (MEMPR), is a first step toward the Province’s goal of developing a new energy efficiency standard for water heating systems in new construction. This groundbreaking new standard would employ a “systems” approach, establishing guidelines for new construction based on the total energy used for water heating within the building envelope The research team has developed a Simulink computer model which, using a one-minute time-step, simulates 24-hour cycles of water heating in a single-family home. The objectives of this thesis are to use that model to simulate a variety of water heating technology combinations, and to devise methods of utilizing the resulting data to evaluate water heating systems as a whole and to quantify each system’s relative energy impact. A metric has been developed to evaluate the efficiency of the system: the system energy factor (SEF) is the ratio of energy used directly to heat water over the amount of energy drawn from conventional fuel sources. The CO2 impact of that energy draw is also considered. Data is generated for cities in three different climates around BC: Kamloops, Victoria and Williams Lake. Electric and gas-fired tank water heaters of various sizes and efficiencies are simulated, along with less traditional energy-saving technologies such as solar-assisted pre-heat and waste water heat recovery components. A total of 7,488 six-day simulations are run, each representing a unique combination of technology, load size, location and season. The resulting data is presented from a variety of angles, including the relative impacts of water heater rating, additional technology type, location and season on the SEF of the system. The interplay between SEF and carbon dioxide production is also examined. These two factors are proposed as the basis for devising performance tiers by which to rank water heating systems. Two proposals are made regarding how these tiers might be organized based on the data presented here, though any tiers will have to be re-evaluated pending data on a wider range of technology combinations. A brief financial analysis is also offered, exploring the potential payback period for various technology combinations in each location. Given current equipment and energy costs, the financial savings garnered by the increase in energy efficiency are not, in most cases, found to be sufficient to justify the expense to the homeowner from a purely fiscal perspective. Additional changes would need to take place to ensure the financial viability of these technologies before large-scale adoption of systems-based standards could be employed. / Graduate

Τα αστροκυττώματα αποτελούν το συχνότερο τύπο πρωτοπαθών όγκων του κεντρικού νευρικού συστήματος (ΚΝΣ) και παραδοσιακά θεωρούνται ότι σχετίζονται με ιδιαίτερα δυσμενή πρόγνωση. Η Συστημική προσέγγιση της καρκινογένεσης, εστιάζοντας στην αποκρυπτογράφηση του τρόπου λειτουργίας και δυναμικής αλληλεπίδρασης πολύπλοκων παθοβιολογικών δικτύων, προσφέρει σήμερα καινούριες ερευνητικές προοπτικές και πιθανές εναλλακτικές, περισσότερο αποτελεσματικές θεραπευτικές στρατηγικές. Οι οιστρογονικοί υποδοχείς και οι συν – ρυθμιστές της μεταγραφής συνιστούν κομβικά σημεία “συνομιλίας” (cross – talk) πολύπλοκων μοριακών οδών του κυττάρου, διαμεσολαβώντας πλήθος κυτταρικών λειτουργιών φυσιολογικά αλλά και σε παθολογικές καταστάσεις, ανάμεσα στις οποίες και ο καρκίνος. Οι παράγοντες EZH2 και SOX2 θεωρούνται μόρια κλειδιά του ρυθμιστικού μεταγραφικού κυκλώματος που χαρακτηρίζει το stemness. Η αποσαφήνιση της συμπεριφοράς του συγκεκριμένου αυτού δικτύου στα διάφορα νεοπλάσματα και ρόλος του σε σχέση με την απόκτηση ιδιότητας καρκινικού stem κυττάρου, θεωρείται καθοριστικής σημασίας στην προσπάθεια ερμηνείας του φαινομένου του καρκίνου ως πολύπλοκο προσαρμόσιμο σύστημα, που θα αναδείξει εναλλακτικούς θεραπευτικούς στόχους και θα επιτρέψει περισσότερο αποτελεσματικές σε σχέση με τις υπάρχουσες παρεμβάσεις. Σκοπός. Υπό το πρίσμα της Συστημικής προσέγγισης της κατανόησης της κακοήθους ανάπτυξης και εξέλιξης των αστροκυτταρικών όγκων, η παρούσα μελέτη διερεύνησε τα επίπεδα έκφρασης του Οιστρογονικού υποδοχέα β (ERβ), και των συν – ρυθμιστών AIB1, TIF2 and PELP1, όπως και την έκφραση των παραγόντων EZH2 και SOX2 σε αστροκυττώματα grade II ως IV και τη συσχέτιση μεταξύ του προφίλ έκφρασης των συγκεκριμένων παραγόντων, με κλινικοπαθολογικά δεδομένα. Υλικό και μέθοδος. Η έκφραση των πρωτεϊνών ERβ, AIB1, TIF2, PELP1, EZH2 και SOX2 εκτιμήθηκε σε 86 περιπτώσεις αστροκυτταρικών όγκων χρησιμοποιώντας τη μέθοδο της ανοσοϊστοχημείας. Είκοσι grade II αστροκυττώματα, 22 grade III αναπλαστικά αστροκυττώματα και 46 grade IV πλειόμορφα γλοιοβλαστώματα (GBM) συμπεριλήφθησαν στη συγκεκριμένη μελέτη. Η μέθοδος με χρήση συστήματος ανίχνευσης EnVision (Envision, Dako, CA, USA) ή MACH4 Universal HRP-Polymer Detection (Biocare Medical, CA, USA) και πρωτογενή αντισώματα έναντι των ERβ (Biogenex, CA, USA), AIB1 (BD Biosciences, Ca, USA), TIF2 (BD Biosciences, Ca, USA), PELP-1/MNAR (Novus Biologicals, CO, USA) EZH2 (Novocastra, UK) και SOX2 (R&D Systems, Inc.) χρησιμοποιήθηκαν στην παρούσα μελέτη. Σε κάθε περιστατικό και για κάθε δείκτη εκτιμήθηκε το ποσοστό των καρκινικών κυττάρων που εμφάνιζαν θετική ανοσοχρώση. Αντιπροσωπευτικές περιοχές επιλέχθηκαν κατόπιν σάρωσης του πλακιδίου σε οπτικό πεδίο μικρής μεγέθυνσης (Χ100), ενώ η καταμέτρηση των θετικών κυττάρων πραγματοποιήθηκε σε μεγάλης μεγέθυνσης πεδίο (400X). Η στατιστική ανάλυση έγινε με τη χρήση του SPSS στατιστικού πακέτου (SPSS©, Release 17.0, Chicago, IL, USA). Τιμές p<0.05 θεωρήθηκαν ως στατιστικά σημαντικές. Αποτελέσματα. Σημαντική μείωση των επιπέδων του ERβ παρατηρήθηκε παράλληλα με την αύξηση του grade. Επιπλέον, η υψηλή ERβ έκφραση αναδείχθηκε ως ανεξάρτητος θετικός προγνωστικός παράγοντας της συνολικής επιβίωσης κατά την πολυπαραγοντική ανάλυση. Η έκφραση των AIB1, TIF2 και PELP1, δε συσχετίσθηκε με αυτή του ERβ, και ακολούθησε αντιστρόφως ανοδική τάση, παράλληλα με την αύξηση του grade. Η στατιστική ανάλυση περαιτέρω, ανέδειξε μία σημαντική αύξηση τόσο των επιπέδων EZH2 όσο και SOX2 στα grade III και IV σε σχέση με τα grade II αστροκυττώματα. Ισχυρή συσχέτιση παρατηρήθηκε ως προς την έκφραση των δύο δεικτών σε όλες τις κατά grade υποομάδες. Η Kaplan-Meier ανάλυση έδειξε ότι, η υψηλή EZH2 και SOX2 πρωτεϊνική έκφραση συνιστούν αρνητικό παράγοντα πρόγνωσης τόσο στο σύνολο των ασθενών όσο και κατόπιν διαστρωμάτωσης κατά grade. Τέλος, η πολυπαραγοντική Cox ανάλυση συνυπολογίζοντας την ηλικία, το φύλο, το grade και την έκφραση των δύο πρωτεϊνών έδειξε ότι μόνο η υψηλή EZH2 έκφραση μαζί με το υψηλό grade, αποτελούν ανεξάρτητους παράγοντες δυσμενούς πρόγνωσης. Συμπεράσματα. Οι παράγοντες ERβ, AIB1, TIF2 και PELP1 ενέχονται στους παθογενετικούς μηχανισμούς ανάπτυξης και εξέλιξης των αστροκυτταρικών όγκων, με τον ERβ να διαδραματίζει προστατευτικό ρόλο και τους AIB1, TIF2 και PELP1 να εμφανίζουν ογκο – προαγωγό δράση. Το ογκογενετικό δυναμικό των παραγόντων AIB1, TIF2 και PELP1 φαίνεται πως διαμεσολαβείται μέσω ανεξάρτητων του οιστρογονικού υποδοχέα μηχανισμών. Η έκφραση του ERβ, διαχωρίζοντας κλινικές εκβάσεις σε ασθενείς ιδίου grade, θα μπορούσε να αποτελέσει ένα χρήσιμο εργαλείο κατά τη λήψη εξατομικευμένων κλινικών αποφάσεων. Οι παράγοντες EZH2 και SOX2, θα μπορούσαν να χρησιμοποιηθούν ως εν δυνάμει δείκτες καρκινικών stem κυττάρων σε αστροκυτταρικούς όγκους, να βοηθήσουν τη βελτιστοποίηση τόσο διαγνωστικών όσο και προγνωστικών διαδικασιών στην κλινική πράξη, και να κατευθύνουν την ανάπτυξη εξατομικευμένων στρατηγικών θεραπείας. / Astrocytic tumors are the most common primary neoplasms of the central nervous system (CNS) and have traditionally been associated with disappointing clinical outcomes. The current challenge is to develop more efficacious and targeted therapeutic paradigms, exploiting the knowledge derived from the systems approach of understanding the complex networks underlying tumor formation and progression. Estrogen receptor beta (ERβ) and co-regulators of transcription AIB1, TIF2 and PELP1, are key components of complex cellular networks and integrate diverse signaling afferents with transcription programs controlling various physiological cellular processes and a variety of disease states including cancer. SOX2 and EZH2 represent crucial components of the reciprocal regulatory circuit that controls stemness. Elucidating the behavior of this particular network in cancer and its role in the formation of putative cancer stem cells is considered essential for the understanding of cancer as an adaptive complex system and subsequently allowing the discovery of more successful therapeutic designs. Purpose. In the context of the systems approach of comprehending tumorigenesis in astrocytomas, we sought to investigate the expression of ERβ and co – regulatory proteins AIB1, TIF1 and PELP1, as well as parallel expression of SOX2 and EZH2 in astrocytomas of various grades, and correlate the protein expression profiles with clinicopathological parameters and patients’ prognosis. Materials and methods. Expression of ERβ, AIB1, TIF2, PELP1, EZH2 and SOX2 was evaluated in 86 cases of astrocytic tumors, using Immunohistochemistry, on formalin-fixed paraffin-embedded tissue sections. Twenty grade II astrocytomas, 22 grade III anaplastic astrocytomas and 46 grade IV glioblastomas multiforme (GBM) were included in this study. Polymer based technique (Envision, Dako, CA, USA) or MACH4 Universal HRP-Polymer Detection (Biocare Medical, CA, USA) and primary antibodies against ERβ1 (Biogenex, CA, USA), AIB1 (BD Biosciences, Ca, USA), TIF2 (BD Biosciences, Ca, USA), PELP-1/MNAR (Novus Biologicals, CO, USA) EZH2 (Novocastra, UK) and SOX2 (R&D Systems, Inc.) were used. In each case, the percentage of cells exhibiting positive staining was determined. Representative areas were selected at low power (x100) magnification. Cell counts were performed at a 400X magnification. Data were analyzed using the SPSS statistical package (SPSS©, Release 17.0, Chicago, IL, USA). The level of significance was set at p-value <0.05. Results. ERβ levels were significantly decreased with the progression of tumors’ grade. High expression of ERβ was an independent favorable prognostic factor on multivariate analysis. Expression of AIB1, TIF2 and PELP1, was not correlated to ERβ expression and followed an opposite trend, with increasing levels in grade III and IV relative to grade II tumors. Univariate survival analysis revealed that high AIB1, TIF2 and PELP1 expression was associated with worse prognosis. Statistical analysis further revealed significantly higher expression of EZH2 and SOX2 in high grade III and IV astrocytomas, compared to low grade II astrocytomas. Strong correlation between EZH2 and SOX2 was also detected within all subgroups according to grade. Kaplan-Meier showed that EZH2 and SOX2 high expression was predictive of worse overall survival in the whole cohort as well as after subgroup analysis by grade. Finally, multivariate Cox analysis that included age, gender, grade, and expression of both proteins, revealed that high EZH2 together with higher grade were strong negative prognostic factors. Conclusions. ERβ, AIB1, TIF2 and PELP1 appear to play an important role in the pathogenesis of astrocytic tumors, with ERβ exhibiting a protective effect, whereas AIB1, TIF2 and PELP1 facilitate malignant progression. AIB1, TIF2 και PELP1 contribution in tumor progression is speculated to be achieved through ERβ independent pathways. Moreover, the expression status of ERβ, by distinguish patient subpopulations with different prognosis within the same grade, could be a useful tool accommodating personalized clinical decision-making. EZH2 and SOX2 may serve as potential cancer stem cell markers in astrocytomas and as such help optimizing diagnostic and prognostic assessments and devising novel individually tailored treatment strategies.

Le nombre des collisions avec des piétons aux passages à niveau restant stable dans les dernières années, c’est un problème majeur au niveau international. Suite à la revue étendue de la littérature, des lacunes scientifiques importantes liées à l’étude du comportement du piéton ont été identifiées. L’objectif principal de ce programme de recherche était de contribuer à mieux comprendre le comportement du piéton aux passages à niveau actifs en Australie, où malgré la mise en place des protections renforcées pour les piétons, le nombre de collisions reste plus important que sur les autres types de passages à niveau. Trois études ont été réalisées pour répondre aux trois buts de recherche que nous nous proposons d'examiner dans le cadre de ce programme. La première étape de recherche qui est exploratoire a été réalisée dans le cadre des études 1 et 2 dont les conclusions ont permis d'identifier les facteurs influençant la prise de décision aux passages à niveau. A la fin de cette étape un nouveau modèle systémique a été développé pour servir d’instrument à l’analyse du comportement du piéton, influencé par des facteurs de tous les niveaux du système. Dans la deuxième étape empirique de recherche, nous avons mené l’étude 3 pour examiner l’impact de facteurs clés sur les comportements à risque dans différentes situations à risque de traversée des piétons. L’articulation des trois études est une illustration des bénéfices associés avec l’utilisation à la fois des méthodes systémiques et traditionnelles, résultant des contributions théoriques et pratiques importantes. / Level crossing collisions with pedestrians are a major issue worldwide and in Australia, where their number remains stable in recent years. An extended review of the literature highlighted a number of important scientific gaps in current knowledge on the factors shaping specifically pedestrian behaviour. The main objective of this research program was to contribute to the better understanding of pedestrian behaviour at active level crossings in Austalia, where a larger number of collisions are reported despite the reinforced safety measures in place. Three research aims were formulated and supported the development of three studies.Study 1 and 2 were part of the first explorative stage of research and informed on the main factors shaping crossing decisions of pedestrians. At the end of this stage a new systems-based framework was developed as a tool for the analysis of pedestrian behaviour as influenced by factors across all system levels. Study 3, part of the empirical stage of research, examined in depth the influence of key precursors of unsafe behaviour across different crossing situations. The articulation of the three studies demonstrates the benefits of using systems-based and traditional individual-centred methods in a complementary manner resulting in important theoretical and practical contributions.

The evidence from the literature suggests that Information Technology adoption (IT) governance in organisations is still a challenge. The diversity of application and the ever-increasing use of IT results in making decisions on IT adoption a major challenge for organisations. The decision about using a particular technology from an organisational perspective is problematic since individual users have different worldviews. The implicit assumption in IT adoption literature is that stakeholders always reach consensus during IT adoption decision making in organisations. This study explored the existing models and frameworks in order to develop a preliminary improved IT adoption governance framework. This study used a case study sequential explanatory mixed methods research approach to validate the preliminary IT adoption governance framework. The first validation phase of the framework was done using a quantitative approach followed by the second validation phase based on qualitative interviews. The last validation was done after integrating the quantitative and qualitative results to produce the refined framework. The results suggest that the developed framework may improve IT adoption governance in organisations. The results showed that the framework components facilitate IT adoption governance in organisations. The results also suggest that the components have an association with each other except for the Technology Acceptance Model component. The results indicate that stakeholder participation and hard systems thinking components have a strong predictive impact on IT governance framework component perception in organisations. The study results suggest that IT adoption decision makers need to balance different stakeholders’ demands during IT adoption decision making in organisations. The framework helps in that regard by reconciling different stakeholders’ demands through collective IT adoption decision making. The strength of the framework is its integration of theories from various disciplines in understanding stakeholder expectations. On that basis the framework is in a better position to offer more insight into understanding challenges of IT adoption decision making than existing frameworks and models. The framework offers a potentially valuable basis for future research in IT adoption decision making in organisations. The results suggest that the framework may facilitate IT adoption in organisations using different components. / Information Science / D. Litt. et Phil. (Information systems)

One of the reasons, why it is difficult to implement the concept of social sustainability into organizations, is its inherent complexity and vagueness. The new Social Sustainability Principles (SSPs) within the Framework for Strategic Sustainable Development (FSSD) offer a clear definition of success for the social system. This study aims to put the new SSPs into an organizational context. It investigates how people-related issues within organizations, discussed in six organizational and management journals, published between 2009 and 2014, are related to the SSPs. One fourth of the 3305 reviewed articles were found to relate to social sustainability. Most of the articles focused on improving performance through aspects related to social sustainability. The articles mainly discussed aspects related to barriers to the SSPs as problems, solutions or positive aspects that could remove barriers to the SSPs. The results show that for organizational research to be able to support organizations moving towards social sustainability, there is a need for a clear definition of success as well as a frame that takes the whole social system into consideration. The FSSD and the SSPs could help to structure the diverse topics, put research problems in a bigger context and discern relevant problems and solutions.

Waste resulting from healthcare activities is hazardous due to its potential risk of infection to healthcare workers, waste workers and the public. Many tools and approaches have been applied in waste management in developed countries, but are not suitable for application in developing countries due to their complexity and extensive data and resource requirements. WasteOpt was therefore developed and applied as an appropriate decision-making tool in the developing country context. WasteOpt comprises of the Analytical Hierarchy Process (AHP), costing and Life cycle management (LCM). The purpose of this study was to identify environmentally sound technologies (ESTs) that minimise the risk of infection by healthcare waste (HCW) in rural clinics. Rural clinics were selected because apart from financial constraints, they are challenged by the lack of procedure, infrastructure and technologies to develop reasonable waste management plans that can be implemented within a practicable time frame. WasteOpt was applied to aid in identifying ESTs in relation to the infection risks and costs of the technologies. Experts in waste management in Lesotho were involved in a workshop for the ranking of technologies. The overall weighting values of the rankings were converted to risk factors for individual options and for alternatives (combination of options). Risk factors were classified as low, medium and high risk. The technologies within a single class were differentiated by analysing the cost of acquiring and running the technology to qualify as ESTs. The ESTs identified for Lesotho are Engineered containers, Refrigerated engineered facility, engineered wheeled transport, detailed procedures, multi chamber incinerator, engineered pit and landfill. Ten (10) clinics in Lesotho were also assessed as case studies using the WHO RAT. The RAT was first modified to include questions on financial management at the clinics. The calculated risk factors were applied to the case studies to assess the risk under which healthcare workers operate in those clinics. The additive minimum risk for the overall life cycle of waste was 4.0 (excluding central treatment and disposal). The clinic workers were found to be at a risk of between 1.1 x 10-4 and 7.8 x 10-5, which proves that rural clinics in Lesotho are still using inappropriate technologies. In terms of financing for waste management, public clinics were found to have little decision-making powers over funds and had less accountability measures. CHAL clinics which are managed by churches in Lesotho had more control of funds and exhibit more accountability. All clinics had no targets for saving funds from waste management activities. WasteOpt can be applied as a decision-making tool for HCW in Lesotho since it overcomes the barriers that inhibit environmentally sound management of HCW in developing countries. In conclusion: WasteOpt can be applied as a decision-making tool for different types of waste by replacing HCW options with respective ones and designing a relevant questionnaire for qualitative data capture. WasteOpt can then be applied in a developing country to aid sustainable waste management decision-making. Informed decision-making helps resource poor managers to select cost-effective but low-risk options, which will be sustainable in the future. / Dissertation (MSc (Environmental Technology))--University of Pretoria, 2007. / Chemical Engineering / unrestricted

AFRIKAANS: Met hierdie studie word gepoog om gemeenteleiers toe te rus om meer effektief leiding te gee. Die Kerk bevind haarself in ’n komplekse samelewing wat tans destruktief op kerkwees inspeel. Om die uitdagings van ons tyd te oorkom sal leiers kreatief en innoverend moet help vorm gee aan nuwe werklikhede. Alternatiewe lense is derhalwe nodig om gemeentes te begelei op ’n uitdagende reis. Die uitdaging vir gemeenteleiers is om kerkwees ontluikend te laat gebeur. Die veronderstelling is dat Kerk organies eerder as meganies en institusioneel tot uitdrukking kom. Leierskap is ’n dinamiese aangeleentheid wat binne gemeentelike en kerkverband moet plaasvind. Binne die Praktiese Teologie word die metodologiese modelle van Zerfass en Heitink gekies om die verkeer tussen teorie en praxis te bevorder. Die Praktiese Teologie word in terme van ’n kommunikatiewe handelingswetenskap met ’n hermeneutiese oriëntasie omskryf. Die ondersoek is hoofsaaklik deduktief van aard. In die proses van teorievorming word teorieë vanuit verskeie dissiplines ontleed en geëvalueer. Prakties-teologiese teorie moet egter praktyk word, en daarom kom die geloofshandelinge van mense hier onder bespreking. Die prakties-teologiese teoretiese raamwerk word nagevors vanuit drie primêre fokuspunte: • Postmodernisme Die postmodernisme is vir die Kerk ’n komplekse realiteit. Die Kerk kan haarself nie losmaak van hierdie werklikheid nie en behoort daarom kennis te neem van hierdie oorwegende tydsgees. Die implikasie hiervan is dat die Kerk in ’n postmoderne konteks hermeneuties verantwoordbaar bly. • Die identiteit van die Kerk Vanuit ’n Bybels-Reformatoriese perspektief is dit duidelik dat die ware Kerk (ecclesia visibilis) sekere kenmerke en eienskappe vertoon. Dog mag die “vorm” wat die Kerk aanneem nie opgaan in hierdie eienskappe en kenmerke nie. Binne die postmoderne konteks blyk Kerkwees meer organies te gebeur. Die Kerk is egter alleen Kerk insoverre haar identiteit in Jesus Christus setel. • Rol van leiers in ’n wêreld wat as kompleks getipeer word Die kompleksiteit van die postmoderne samelewing het tot gevolg dat leierskapteorie en praktyk verby die punt van beplanning, organisering en beheer (aanvaarbare bestuurswetenskaplike metodiek) ontwikkel het. Leierskap in die Kerk is ’n kollektiewe aangeleentheid en moet derhalwe holisties benader en bestuur word. Dit geskied dinamies en relasioneel. Aan die hand van die empiriese ondersoek word nuwe riglyne vir die bedieningspraktyk daargestel. ENGLISH:This study aims to equip leaders of congregations to become more efficient leaders. The Church finds herself in a complex society which currently has a destructive influence on the realisation of the Church. To overcome the challenges of our time, leaders must help to shape new realities in a creative and innovative way. An alternative way of looking at the issues are therefore needed to guide congregations on a challenging journey. The challenge for congregational leaders is to let the realisation of the Church take place in a revealing and developing manner. The assumption is that the Church is realised organically rather than mechanically and institutionally. Leadership is a dynamic matter that should be realized in congregational and ecumenical context. In Practical Theology, the methodological models of Zerfass and Heitink are selected to promote the interaction between theory and praxis. Practical Theology is defined in terms of a communicative per formative science with a hermeneutical orientation. The investigation is mainly deductive in nature. In the process of theorising, theories from different disciplines are analysed and evaluated. Practical-theological theory must become practice, however, and for that purpose the religious acts of people are discussed here. The practical-theological theoretical framework is researched from three primary focal points: • Postmodernism Postmodernism is a complex reality for the Church. The Church cannot distance herself from this reality, and should therefore take cognisance of this prevailing spirit of our time. The implication of this is that the Church remains hermeneutically accountable in a postmodern context. • The identity of the Church From a Biblical-Reformational perspective, it is clear that the true Church (ecclesia visibilis) displays certain features and characteristics. Yet, the “form” which the Church adopts may not be reduced to these features and characteristics. In the postmodern context, Church realisation appears to be happen more in an organic manner. However, the Church is only Church in as far as her identity is rooted in Christ. • The role of leaders in a world typified as complex Because of the complexity of postmodern society, leadership theory and practice developed beyond the point of planning, organising and control (acceptable managerial scientific methodology). Leadership in the Church is a collective matter and as such it must be approached and managed in a holistic way, by means of dynamic and relational methods. Based on the empirical investigation, new guidelines are developed for ministry practice. / Thesis (PhD)--University of Pretoria, 2009. / Practical Theology / unrestricted

<p>The modern world of manufacturing is in the middle of an industrial revolution with the digital and physical worlds integrating through cyber-physical systems.  Through a virtual model that is able to communicate with its physical system known as the Digital Twin, catered decisions can be made based on the current state of the system.  The digital twin presents immense opportunities and challenges as there is a greater need to understand how these new technologies work together. </p> <p><br></p> <p>This thesis is an experimental investigation of the characteristics of the essential components of the Digital Twin.  A Digital Twin Framework is developed to explore the impacts of model accuracy and update frequency on the system’s performance measure. A simple inventory management system and a more complex manufacturing plant is modeled through the framework providing a method to study the interactions of the physical and digital systems with empirical data.</p> <p><br></p> <p><br></p> <p>As the decision policies are affected by the state changes in the system, designing the Digital Twin must account for the direct and indirect impact of its components. </p> <p>Furthermore, we show the importance of communication and information exchange between the Digital Twin and its physical system.  A key characteristic for developing and applying a digital twin is to monitor the update frequency and its impact on performance.  Through the study there are implications of optimal combinations of the digital twin components and how the physical system responds.  There are also limits to how effective the Digital Twin can be in certain instances and is an area of research that needs further investigation.  </p> <p><br></p> <p>The goal of this work is to help practitioners and researchers implement and use the Digital Twin more effectively.  Better understanding the interactions of the model components will help guide designing Digital Twins to be more effective as they become an integral part of the future of manufacturing.</p>

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