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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
461

Optimizing Test Pattern Generation Using Top-Off ATPG Methodology for Stuck–AT, Transition and Small Delay Defect Faults

Gill, Arjun 03 October 2013 (has links)
The ever increasing complexity and size of digital circuits complemented by Deep Sub Micron (DSM) technology trends today pose challenges to the efficient Design For Test (DFT) methodologies. Innovation is required not only in designing the digital circuits, but also in automatic test pattern generation (ATPG) to ensure that the pattern set screens all the targeted faults while still complying with the Automatic Test Equipment (ATE) memory constraints. DSM technology trends push the requirements of ATPG to not only include the conventional static defects but also to include test patterns for dynamic defects. The current industry practices consider test pattern generation for transition faults to screen dynamic defects. It has been observed that just screening for transition faults alone is not sufficient in light of the continuing DSM technology trends. Shrinking technology nodes have pushed DFT engineers to include Small Delay Defect (SDD) test patterns in the production flow. The current industry standard ATPG tools are evolving and SDD ATPG is not the most economical option in terms of both test generation CPU time and pattern volume. New techniques must be explored in order to ensure that a quality test pattern set can be generated which includes patterns for stuck-at, transition and SDD faults, all the while ensuring that the pattern volume remains economical. This thesis explores the use of a “Top-Off” ATPG methodology to generate an optimal test pattern set which can effectively screen the required fault models while containing the pattern volume within a reasonable limit.
462

Ranked Retrieval in Uncertain and Probabilistic Databases

Soliman, Mohamed January 2011 (has links)
Ranking queries are widely used in data exploration, data analysis and decision making scenarios. While most of the currently proposed ranking techniques focus on deterministic data, several emerging applications involve data that are imprecise or uncertain. Ranking uncertain data raises new challenges in query semantics and processing, making conventional methods inapplicable. Furthermore, the interplay between ranking and uncertainty models introduces new dimensions for ordering query results that do not exist in the traditional settings. This dissertation introduces new formulations and processing techniques for ranking queries on uncertain data. The formulations are based on marriage of traditional ranking semantics with possible worlds semantics under widely-adopted uncertainty models. In particular, we focus on studying the impact of tuple-level and attribute-level uncertainty on the semantics and processing techniques of ranking queries. Under the tuple-level uncertainty model, we introduce a processing framework leveraging the capabilities of relational database systems to recognize and handle data uncertainty in score-based ranking. The framework encapsulates a state space model, and efficient search algorithms that compute query answers by lazily materializing the necessary parts of the space. Under the attribute-level uncertainty model, we give a new probabilistic ranking model, based on partial orders, to encapsulate the space of possible rankings originating from uncertainty in attribute values. We present a set of efficient query evaluation algorithms, including sampling-based techniques based on the theory of Markov chains and Monte-Carlo method, to compute query answers. We build on our techniques for ranking under attribute-level uncertainty to support rank join queries on uncertain data. We show how to extend current rank join methods to handle uncertainty in scoring attributes. We provide a pipelined query operator implementation of uncertainty-aware rank join algorithm integrated with sampling techniques to compute query answers.
463

Top - Down Design eines universellen Kegelrollenlagermodells in Pro/MECHANICA

Kloninger, Paul 12 May 2011 (has links) (PDF)
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.
464

Development of a Rep-inducible, BBTV-based expression system in banana

Bolton, Clair Louise January 2009 (has links)
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.
465

Board characteristics and firm performance: evidence from New Zealand

Bathula, Hanoku January 2008 (has links)
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.
466

The murder in merger developmental processes of a corporate merger and the struggle between life and death impulses /

De Gooijer, Jinette. January 2006 (has links)
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).
467

Transgenic resistance to PMTV and PVA provides novel insights to viral long-distance movement /

Germundsson, Anna, January 2005 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.
468

Neue Methoden zur Verhaltensmodellierung und Charakterisierung eines analog-digital-Systems am Beispiel einer Phasenregelschleife

Hinz, Michael January 2008 (has links)
Zugl.: Braunschweig, Techn. Univ., Diss., 2008
469

Modulare Datentypdefinitionen und ihre Beziehungen zur Logik erster Stufe

Treinen, Ralf. Unknown Date (has links) (PDF)
Universiẗat, Diss., 1991--Saarbrücken.
470

Hierarchical optimization of large-scale analog, mixed-signal circuits based-on Pareto-optimal fronts

Zou, Jun January 2009 (has links)
Zugl.: München, Techn. Univ., Diss., 2009

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