In dieser Präsentation wird das universelle FE-Modell eines Kegelrollenlagers vorgestellt. Mittels eines Pro/ENGINEER-Layouts, basierend auf dem Top-Down Designkonzept, kann automatisch innerhalb einer kurzen Bearbeitungszeit ein geprüftes und lauffähiges FE-Modell eines Kegelrollenlagers abgeleitet werden. Dieses Modell kann z.B. in großen Getriebemodellen eingebaut werden, um eine quasistatische Betrachtung mit korrekten Lagersteifigkeiten zu ermöglichen.

Banana bunchy top is regarded as the most important viral disease of banana, causing significant yield losses worldwide. The disease is caused by Banana bunchy top virus (BBTV), which is a circular ssDNA virus belonging to the genus Babuvirus in the family Nanoviridae. There are currently few effective control strategies for this and other ssDNA viruses. “In Plant Activation” (InPAct) is a novel technology being developed at QUT for ssDNA virus-activated suicide gene expression. The technology exploits the rolling circle replication mechanism of ssDNA viruses and is based on a unique “split” gene design such that suicide gene expression is only activated in the presence of the viral Rep. This PhD project aimed to develop a BBTV-based InPAct system as a suicide gene strategy to control BBTV. The BBTV-based InPAct vector design requires a BBTV intergenic region (IR) to be embedded within an intron in the gene expression cassette. To ensure that the BBTV IR would not interfere with intron splicing, a TEST vector was initially generated that contained the entire BBTV IR embedded within an intron in a β-glucuronidase (GUS) expression vector. Transient GUS assays in banana embryogenic cell suspensions indicated that cryptic intron splice sites were present within the IR. Transcript analysis revealed two cryptic intron splice sites in the Domain III sequence of the CR-M within the IR. Removal of the CR-M from the TEST vector resulted in an enhancement of GUS expression suggesting that the cryptic intron splice sites had been removed. An InPAct GUS vector was subsequently generated that contained the modified BBTV IR, with the CR-M (minus Domain III) repositioned within the InPAct cassette. Using transient histochemical and fluorometric GUS assays in banana embryogenic cells, the InPAct GUS vector was shown to be activated in the presence of the BBTV Rep. However, the presence of both BBTV Rep and Clink was shown to have a deleterious effect on GUS expression suggesting that these proteins were cytotoxic at the levels expressed. Analysis of replication of the InPAct vectors by Southern hybridisation revealed low levels of InPAct cassette-based episomal DNA released from the vector through the nicking/ligation activity of BBTV Rep. However, Rep-mediated episomal replicons, indicative of rolling circle replication of the released circularised cassettes, were not observed. The inability of the InPAct cassette to be replicated was further investigated. To examine whether the absence of Domain III of the CR-M was responsible, a suite of modified BBTV-based InPAct GUS vectors was constructed that contained the CR-M with the inclusion of Domain III, the CR-M with the inclusion of Domain III and additional upstream IR sequence, or no CR-M. Analysis of replication by Southern hybridisation revealed that neither the presence of Domain III, nor the entire CR-M, had an effect on replication levels. Since the InPAct cassette was significantly larger than the native BBTV genomic components (approximately 1 kb), the effect of InPAct cassette size on replication was also investigated. A suite of size variant BBTV-based vectors was constructed that increased the size of a replication competent cassette to 1.1 kbp through to 2.1 kbp.. Analysis of replication by Southern hybridisation revealed that an increase in vector size above approximately 1.5 - 1.7 kbp resulted in a decrease in replication. Following the demonstration of Rep-mediated release, circularisation and expression from the InPAct GUS vector, an InPAct vector was generated in which the uidA reporter gene was replaced with the ribonuclease-encoding suicide gene, barnase. Initially, a TEST vector was generated to assess the cytotoxicity of Barnase on banana cells. Although transient assays revealed a Barnase-induced cytotoxic effect in banana cells, the expression levels were sub-optimal. An InPAct BARNASE vector was generated and tested for BBTV Rep-activated Barnase expression using transient assays in banana embryogenic cells. High levels of background expression from the InPAct BARNASE vector made it difficult to accurately assess Rep-activated Barnase expression. Analysis of replication by Southern hybridisation revealed low levels of InPAct cassette-based episomal DNA released from the vector but no Rep-mediated episomal replicons indicative of rolling circle replication of the released circularised cassettes were again observed. Despite the inability of the InPAct vectors to replicate to enable high level gene expression, the InPAct BARNASE vector was assessed in planta for BBTV Rep-mediated activation of Barnase expression. Eleven lines of transgenic InPAct BARNASE banana plants were generated by Agrobacterium-mediated transformation and were challenged with viruliferous Pentalonia nigronervosa. At least one clonal plant in each line developed bunchy top symptoms and infection was confirmed by PCR. No localised lesions were observed on any plants, nor was there any localised GUS expression in the one InPAct GUS line challenged with viruliferous aphids. The results presented in this thesis are the first study towards the development of a BBTV-based InPAct system as a Rep-activatable suicide gene expression system to control BBTV. Although further optimisation of the vectors is necessary, the preliminary results suggest that this approach has the potential to be an effective control strategy for BBTV. The use of iterons within the InPAct vectors that are recognised by Reps from different ssDNA plant viruses may provide a broad-spectrum resistance strategy against multiple ssDNA plant viruses. Further, this technology holds great promise as a platform technology for the molecular farming of high-value proteins in vitro or in vivo through expression of the ssDNA virus Rep protein.

Due to various corporate scandals and failures, there has been a renewed interest on the role of boards in the performance of firms. This thesis examines the relationship between the key board characteristics and firm performance. Unlike most studies on boards which predominantly use only financial variables affecting governance, I take a different approach by combining them with non-financial variables. This combined set of variables is used for theoretical and empirical modelling. Based on the extant literature, I develop a conceptual framework and a set of hypotheses to examine the relationship between board characteristics and firm performance. Board characteristics considered in this research include board size, director ownership, CEO duality, gender diversity, educational qualification of board members and number of board meetings. Additionally, I use board size as a moderating variable to examine how the effect of other board characteristics is contingent on board size. Firm performance is measured by return on assets. I test my hypotheses on a longitudinal sample of 156 firms over a four year period from 2004 to 2007. My sample includes all firms listed on New Zealand stock exchange as on November 2007. Empirical analysis is undertaken using Generalised Least Squares analyses. The findings of the study show that board characteristics such as board size, CEO duality and gender diversity were positively related with firm performance, where as director ownership, board meetings and the number of board members with PhD level education was found to be negatively related. Board size was found to be moderating some of these relationships, indicating the critical role being played by board size in the design and role of corporate boards. The findings also provide partial evidence to different governance theories, further indicating the need for theoretical pluralism to gain insights into boards’ functioning. The study contributes to the understanding of board-performance link by examining both the traditional variables such as board size, CEO duality, and number of board meetings as well as other organisational attributes such as gender diversity and competence variables represented by women and PhD holders, respectively. The theoretical framework and the findings of my thesis are expected to stimulate scholars for further research to identify the contingency conditions upon which the board characteristics and firm performance may be dependent.

Thesis (PhD) -- Swinburne University of Technology, Australian Graduate School of Entrepreneurship, 2006. / Submitted for the degree of Doctor of Philosophy - Australian Graduate School of Entrepreneurship, Swinburne University of Technology, 2006. Typescript. Includes bibliographical references (p. 251-263).

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Zugl.: Braunschweig, Techn. Univ., Diss., 2008

Universiẗat, Diss., 1991--Saarbrücken.

Zugl.: München, Techn. Univ., Diss., 2009

Μία διαδεδομένη τεχνική που χρησιμοποιείται για την επίτευξη αποδοτικής αναζήτησης περιεχομένου είναι η κατηγοριοποίηση αυτού σε ταξονομίες ετικετών, δηλαδή σε δενδρικές <<ΕΙΝΑΙ-ΕΝΑ>> ιεραρχίες λέξεων-κλειδιών που παρέχουν οι χρήστες. Κάθε κόμβος της δενδρικής δομής αντιστοιχεί σε μία ετικέτα της ταξονομίας. Στην παρούσα διπλωματική εργασία θα γίνει χρήση τέτοιων ταξονομιών ετικετών, όπου κάθε αντικείμενο επισημαίνεται από τους χρήστες με μία ή περισσότερες ετικέτες. Το περιβάλλον το οποίο θα ορίσουμε είναι ιδιαίτερα δυναμικό, με την έννοια ότι η προσθαφαίρεση και τροποποίηση των ετικετών από τους χρήστες είναι συνεχής καθώς και ότι αντικείμενα μπορούν να προσθαφαιρούνται συνεχώς. Στο περιβάλλον αυτό θα στοχεύσουμε στην αποδοτική ιεραρχημένη ανάκτηση περιεχομένου. Πρωταρχικό στόχο αποτελεί η δημιουργία μετρικών ομοιότητας μεταξύ ερωτημάτων, τα οποία υποβάλλονται από χρήστες, και του αποθηκευμένου και κατηγοριοποιημένου περιεχομένου. Οι μετρικές αυτές θα βασίζονται στη σημασιολογική απόσταση των κόμβων των ταξονομιών από τους όρους των υποβληθέντων ερωτημάτων (οι οποίοι όροι θα πρέπει επίσης να αποτελούν κόμβους της ταξονομίας). Βάσει των παραπάνω μετρικών θα σχεδιαστούν και θα υλοποιηθούν αλγόριθμοι για την ανάκτηση των k πιο σχετικών αντικειμένων, οι οποίοι θα αποτελούν επεκτάσεις των βασικών αλγορίθμων κατωφλίου του Fagin (Fagin's Threshold Algorithms - TA). Στην προτεινόμενη προσέγγιση θα καμφθεί η απαίτηση της προΰπαρξης ανεστραμμένων ευρετηρίων. Αντίθετα, τα απαιτούμενα (από τους αλγορίθμους του Fagin) ανεστραμμένα ευρετήρια να κατασκευάζονται δυναμικά κατά την απάντηση των ερωτημάτων. / The spark for this work stems from the recent explosion in social media production, the proven interest of users to tag this media, and on the proven capability of semantically rich taxonomies to appropriately classify content. The rich annotations/tags provided for social media offer a great basis for taxonomies. Noting that web search increasingly involves taxonomies, and that there exists already a rich set of taxonomies for many different fields, which can help classify tags, we target the problems associated with efficient taxonomy-based ranked retrieval in social web environments. In a social-tag taxonomies environment, each tag (taxonomy node) is associated with all documents tagged with this tag. Queries are formulated using tags. The environment is highly dynamic, as documents and tags-documents associations are being added and/or deleted constantly. This dynamism can render as highly inefficient the traditional approaches to ranked retrieval, which are based on text indices, due to the high index creation, maintenance, and use costs. We first adapt similarity measures between tag queries and documents, which are based on well-established principles of taxonomy-based search. We then develop algorithms for top-k queries exploiting taxonomic knowledge. We contribute a suit of top-k algorithms, coined TREATS (ThREshold Algorithms on TaxonomieS). Our first algorithm shows how to build per-tag inverted indices (required by the well-established Threshold Algorithms (TA) for top-k query processing). In this way, we port optimal ranked retrieval algorithms into the taxonomy realm. Our second algorithm, TREATS-sorted, shares the same principles as TA-sorted, but without the need to maintain any inverted text indices! This introduces significant savings: First, in terms of storage required to store the indices. Second, for the overhead for building and maintaining indices. And third, for the overhead incurred during query execution for accessing indices. Our third algorithm, TREATS-Labelled, further exploits the taxonomic structure in order to introduce large additional performance benefits. We also prove the correctness and (instance-)optimality of TREATS. Finally, we have implemented all algorithms and evaluated their efficiency against the baseline TA-random and TA-sorted algorithms, using real data sets with different characteristics.

Thesis (MPhil)--Stellenbosch University, 2012 / ENGLISH ABSTRACT: In small to medium sized enterprises (SMEs) top management is responsible for the risk management in their company. In today‟s world, businesses are relying more and more heavily on IT and often this can be seen as a huge risk. As a potential risk factor and an integral part of any business, IT therefore falls under the portfolio of top management. However, there is a general perception, especially among dedicated IT professionals, that there is a gap between business, that is top management, and IT and that successful communication is not always achieved. The lack of successful communication between top management and IT role players could have a negative impact on a business‟ ability to operate fully. This study is therefore concerned with the investigation of how top management (the IT decision makers in a company) engage in the discourse of IT. It aims to identify whether a communication gap between business (top management) and IT truly does exist and, if so, why. The data for this study takes the form of recorded, semi-structured interviews with IT role-players and directors/managers who have IT as part of their portfolio, from ten SMEs in the greater Cape Town area. This study is undertaken in the framework of semantic discourse analysis, concentrating on two notions of coherence, that of van Dijk‟s (1985) model of macrostructures and Brown and Yule‟s (1983) notion of „discourse topic‟. This approach is used in order to analyse the transcribed interviews with both top management and IT role players in order to determine whether the perception of a communication gap between business (top management) and IT is true and if so, what the reasons for this communication gap are. The analysis of the transcriptions allows the researcher to confirm the perception that a communication gap does exist and to identify two possible reasons as to why this communication gap exists, firstly, that there seems to be a lack of communication between IT and top management and, secondly, that top management‟s interpretation of what IT means to their company differs from that of their IT role players. / AFRIKAANSE OPSMOMMING: In klein tot mediumgrootte ondernemings (KMOs) is topbestuur verantwoordelik vir die risikobestuur in hul maatskappy. In vandag se wêreld, maak besighede meer en meer staat op IT en dit kan dikwels beskou word as 'n groot risiko. As 'n potensiële risikofaktor en' n integrale deel van enige besigheid, val dit dus onder die portefeulje van die top bestuur. Daar is egter 'n algemene persepsie, veral onder toegewyde IT-profesionele, dat daar' n gaping tussen die besigheid, in ander woorde die topbestuur, en IT bestaan en dat suksesvolle kommunikasie nie altyd bereik word nie. Die gebrek aan suksesvolle kommunikasie tussen topbestuur en IT kan 'n negatiewe impak op' n onderneming se vermoë om ten volle te funksioneer he. Hierdie studie is dus gemoeid met die ondersoek van hoe topbestuur (die IT-besluitnemers in 'n maatskappy) betrokke raak in die diskoers met IT. Die doel is om vas te stel of 'n kommunikasie gaping tussen die besigheid (topbestuur) en IT werklik bestaan, en indien wel, waarom te identifiseer. Die data vir hierdie studie neem die vorm van aangetekende, semi-gestruktureerde onderhoude met rolspelers en direkteure / bestuurders wat IT as deel van hul portefeulje het in tien KMOs in die groter Kaapstad-gebied. Hierdie studie is onderneem met die raamwerk van`n semantiese diskoers-analise, en konsentreer op die twee begrippe van samehang, dié van Van Dyk (1985) se model van makrostrukture en Brown en Yule (1983) se idee van `n 'diskoers onderwerp'. Hierdie benadering word gebruik om die getranskribeerde onderhoude met beide topbestuur en IT-rolspelers te analiseer en ten einde te bepaal of die persepsie van 'n kommunikasie gaping tussen die besigheid (topbestuur) en IT-rolspelers waar is en indien wel, wat die redes vir hierdie kommunikasie gaping is. Die ontleding van die transkripsies stel die navorser in staat om die persepsie dat 'n kommunikasie gaping bestaan te bevestig en om twee moontlike redes daarvoor te identifeer, in die eerste plek dat dit lyk asof daar' n gebrek aan kommunikasie tussen IT-rolspelers en die topbestuur bestaan, en tweedens, dat die topbestuur se interpretasie van wat IT beteken vir hul maatskappy verskil van dié van hul IT-rolspelers.