Thesis (M.S.)--University of Michigan, Ann Arbor, 1975. / Typescript (photocopy). Includes bibliographical references (leaves 57-60). Also issued in print.

Thesis (M.S.)--University of Michigan, 1983.

Thesis (M.S.)--University of Michigan, 1956.

Thesis (M.S.)--University of Michigan, Ann Arbor, 1975. / Typescript (photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 57-60).

Η παρούσα μελέτη εδράζεται κυρίως σε σχόλια του Πρόκλου μέσα από την εκτενή πραγματεία του Εις τον Τίμαιον Πλάτωνος όπου διαπιστώνουμε ότι ως εν ταυτώ επιστήμων και μεταφυσικός προσεγγίζει το φυσικό περιβάλλον με βάση ένα παράδειγμα τελολογικό, θείων προδιαγραφών σύμφωνα με το οποίο εντοπίζει στις διαδικασίες του μία προϊούσα βελτιωτική εξέλιξη, η οποία θα το οδηγήσει μέσα από αυστηρές κανονικότητες στην ολοκλήρωσή του. Είναι μάλιστα χαρακτηριστικό το ότι, με το να αποδίδει στο κοσμικό σύμπαν και προσωπικά ιδιώματα, το παρουσιάζει να αρθρώνεται στην εξέλιξή του με ορμικά, βουλητικά και έλλογα στοιχεία. Παρουσιάζει δηλαδή ένα σύμπαν να αφομοιώνει βαθμιαία το σύνολο των θείων χορηγιών και να πορεύεται με συνειδητό τρόπο στην πραγμάτωση των δυνατοτήτων που άνωθεν έχει λάβει. Παρ’ όλο που ο Πρόκλος επιμένει ιδιαίτερα στο να χρησιμοποιεί τα μαθηματικά και την φυσική επιστήμη, οι τελικές εκτιμήσεις του σε κάθε περίπτωση είναι θεολογικές, με ισχυρή πάντως την στήριξη της φιλοσοφίας τόσο από πλευράς ιστορικής όσο και συστηματικής. Προβάλλει ένα σύμπαν το οποίο συνεχώς πορεύεται στο να εξομοιωθεί με το θείον και έτσι να υπερβεί τις όποιες ατέλειες έχει, οι οποίες περιορίζουν – έστω και όχι σε μόνιμη βάση - την ανταπόκρισή του στην πληρότητα. Από έναν τέτοιο σχεδιασμό απουσιάζουν το οιοδήποτε μοντέλο περιγραφής που στηρίζεται στην τυχαιότητα, η επιμονή στον εντοπισμό απόλυτα προβλέψιμων καταστάσεων μηχανιστικής μετάβασης από το προηγούμενο στο επόμενο και η αναζήτηση νόμων που έχουν αποκλειστικά και μόνον φυσικοεμπειρική εξήγηση και κινούνται στον ορίζοντα της τυπικής επαναληπτικότητας. Υπό τους ανωτέρω όρους, θα μπορούσαμε να υποστηρίξουμε ότι διατυπώνεται μία θεωρία του οικοκεντρισμού καθώς το φυσικό περιβάλλον αντιμετωπίζεται ως ολότητα οργανική, όπου αναγκαστικά αποκλείονται οι διορθωτικές παρεμβάσεις μιας τάξης ορισμένων όντων σε βάρος κάποιων άλλων αφού δεν αποδίδεται προτεραιότητα σε κυριαρχικού τύπου ιεραρχήσεις αλλά σ’ εκείνη την αμοιβαιότητα που διασώζει την ιδιαιτερότητα των συμβαλλομένων παραγόντων. Τα ανωτέρω, μάλιστα, συναρτώνται με μία επιμελημένη οριοθέτηση του ζητήματος περί των αξιών και των γενικότερων προϋποθέσεων που συστηματικά το διαμορφώνουν. / The present study is grounded upon Proclus’ comments in his On Plato’s Timaeus. Taking the point of view of both a metaphysician and scientist, Proclus approaches to the problem of natural environment on the basis of a teleological and theological paradigm. According to that paradigm, the environment is subject to a process of development thanks to which (and by means of austere regularities) it will be lead to its accomplishment. It is suggestive that Proclus assigns to cosmos/universe personal features and, hence, attributes to it features of a rational and willing nature. In this way, the universe is presented as gradually absorbing the whole of divine assignments and as processing, in a conscious way, towards the realisation of the possibilities it has been endowed with. Even though Proclus keeps on using mathematics and physical sciences, his final claims are theological, albeit supported by philosophical claims with historical and systematic character. The universe tends to be assimilated with the divine and to overcome thereby the deficiencies which limit, though temporarily, its fulfilling the demand of integrity. In Proclus’ system there is no pattern of accidental outcomes, no reference to explanations of mechanical character and no appeal to mere physico-empirical laws which explain physical regularities. The present study claims that Proclus formulates an eco-centric theory, since the physical environment is considered an organic totality, within which there is no place for interventions at the expense of undermining a certain kind of beings and, correlatively, for any privilege accorded to hierarchically higher kinds of beings. Instead, this universe is grounded on such mutual a dependence which presupposes the particularity of beings.

This thesis is germane to body-centric communication measurements and analyses at different frequency bands. It presents measurements and analyses of the radio channels for humans. This research contains a novel and comprehensive study of body-centric single input multiple output (SIMO) diversity. This has included the analyses of diversity techniques with off-body communications in different settings within indoor environments. The objectives in this research are; investigating the benefits of using multiple antennas for off-body and on-body channels and studying the performance of diversity antennas for off-body in different environments with both genders. A further novel aspect of this thesis has been concerned with off-body channel characteristics using software defined radio (SDR) and LabVIEW using different modulation schemes for measurements and analyses. This method combines processing and control in software, paired with SDR for the over the air interface. The combination of SDR and LabVIEW is shown to provide a platform to facilitate experiments in the presence of humans that is useful for prototyping different types of radio channels. This method also gives a new aspect for a novel treatment of a 2x2 body-centric multiple input multiple output (MIMO) system. It is shown how the difficulties associated with implementing MIMO systems can be overcome by using SDR combined with LabVIEW. Studying the effects of water in the body-centric communication channels are also a new area of research presented here. This work has shown how water encapsulated within Polyacrylamide gel can be exploited as a cheap and available material to enhance the performance of on-body antennas. It is shown that water gives 1–3dB enhancements from the measurements of SIMO and MIMO systems with the human presence.

The rapid development in wireless technologies and multimedia services has radically shifted the major function of the current Internet from host-centric communication to service-oriented content dissemination, resulting a mismatch between the protocol design and the current usage patterns. Motivated by this significant change, Information-Centric Networking (ICN), which has been attracting ever-increasing attention from the communication networks research community, has emerged as a new clean-slate networking paradigm for future Internet. Through identifying and routing data by unified names, ICN aims at providing natural support for efficient information retrieval over the Internet. As a crucial characteristic of ICN, in-network caching enables users to efficiently access popular contents from on-path routers equipped with ubiquitous caches, leading to the enhancement of the service quality and reduction of network loads. Performance analysis and optimisation has been and continues to be key research interests of ICN. This thesis focuses on the development of efficient and accurate analytical models for the performance evaluation of ICN caching and the design of optimal caching management schemes under practical network configurations. This research starts with the proposition of a new analytical model for caching performance under the bursty multimedia traffic. The bursty characteristic is captured and the closed formulas for cache hit ratio are derived. To investigate the impact of topology and heterogeneous caching parameters on the performance, a comprehensive analytical model is developed to gain valuable insight into the caching performance with heterogeneous cache sizes, service intensity and content distribution under arbitrary topology. The accuracy of the proposed models is validated by comparing the analytical results with those obtained from extensive simulation experiments. The analytical models are then used as cost-efficient tools to investigate the key network and content parameters on the performance of caching in ICN. Bursty traffic and heterogeneous caching features have significant influence on the performance of ICN. Therefore, in order to obtain optimal performance results, a caching resource allocation scheme, which leverages the proposed model and targets at minimising the total traffic within the network and improving hit probability at the nodes, is proposed. The performance results reveal that the caching allocation scheme can achieve better caching performance and network resource utilisation than the default homogeneous and random caching allocation strategy. To attain a thorough understanding of the trade-off between the economic aspect and service quality, a cost-aware Quality-of-Service (QoS) optimisation caching mechanism is further designed aiming for cost-efficiency and QoS guarantee in ICN. A cost model is proposed to take into account installation and operation cost of ICN under a realistic ISP network scenario, and a QoS model is presented to formulate the service delay and delay jitter in the presence of heterogeneous service requirements and general probabilistic caching strategy. Numerical results show the effectiveness of the proposed mechanism in achieving better service quality and lower network cost. In this thesis, the proposed analytical models are used to efficiently and accurately evaluate the performance of ICN and investigate the key performance metrics. Leveraging the insights discovered by the analytical models, the proposed caching management schemes are able to optimise and enhance the performance of ICN. To widen the outcomes achieved in the thesis, several interesting yet challenging research directions are pointed out.

During last decade UML have to face different tricky challenges. For instance as a single unified, general purpose modeling language it should offer simple and explicit semantic which can be applicable to wide range of domains. Due to significant shift of focus from software to system “software-centric” attitude of UML has been exposed. So need of certain domain specific language is always there which can address problems of system rather then software only i.e. motivation for SysML. In this thesis SysML is evaluated to analyze its suitability for system engineering applications. A evaluation criteria is established, through which appropriateness of SysML is observed over system development life cycle. The study is conducted by taking case example of real life i.e. automobile product. Results of research not only provide an opportunity to get inside into SysML architecture but also offer an idea of SysML appropriateness for multidisciplinary product development

While collaborative engineering in outsourcing projects presents potential benefits to the partners, it involves some risks and reasonable concerns. First, a poor mechanism of data exchange and data communication can lead to loss of effectiveness and efficiency of the project. Second, collaborative engineering requires partners to adapt a common business process, which often means moving away from a familiar way of working. Thus, it is crucial to find an optimal way a collaboration can be achieved with the lowest waste due to changes in communication practices, and losses in efficiency due to asynchronous processes or big amount of exchange data. The main goal of this thesis is to connect two aspects in a collaboration: data-exchange and process-based execution. The main reason to do so is to resolve a problem with a weak control over information needed for successful project execution. Three research methods are used in this work: a case study to analyze how collaboration is performed in the industry and which problems exist; a literature review to understand how existing collaboration tools can be adapted to help solving the identified problems; and a prototypical implementation to show how automated versioning of engineering knowledge can be added to the union of data exchange and process-based aspects. The case study was performed and a list of business requirements was presented. Based on the list of requirements, solutions within the literature were searched. A process-based artifact-centric concept was applied to the case study scenario. Objectives are achieved, however, the problem was shown on an example of one company, which presents a limitation, as generalization has not been proved.

TCP/IP protocol gradually exposes many shortcomings such as poor scalability and mobility. Content-Centric Networking is a new architecture which cares about the content itself rather than its source. Therefore, this paper proposes a novel IoV architecture which based on Content-Centric Networking and tests its transmission interference time, transmission delay, and throughout in network layer. The experimental results show that the novel architecture is superior to the current IoV in the communication performance.