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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.
1

An exploratory study of localisation drivers and barriers of oil and gas service firms : a case study approach

McDonald, Jeff January 2017 (has links)
The purpose of this thesis is to explore and understand the ‘localisation’ phenomenon from a geographical, cultural, technical and governmental theme to help explain why the level of local content in the oil and gas engineering and technical services private sector tends to flatten out at specific engineering and management skillsets in order to balance quality and delivery of the service and maintain operational excellence. Five research objectives were developed to achieve the research aim to provide a clear understanding, from a corporate strategic perspective, of the drivers and perceived barriers to successful localisation. For the purposes of this thesis, the term "localisation" is understood to mean “when a local national is filling a required job sufficiently competently to fulfil organisational needs” (Potter 1989). Due to the nature of investigation, this study adopted a qualitative inquiry. Thus, a mix of qualitative data collection methods were used such as document, experienced observation, and interviews with senior managers at the corporate strategic level of the business. An interview guide was developed from a conceptual framework generated from the literature review. The study targeted an ‘elite’ sample of oil and gas executives/ managers who are considered role models in the case study organisation. This study argues that a form of grounded theory/qualitative inquiry is adopted during data analysis using open, axial, and selective coding, leading to an evolved conceptual framework of localisation drivers and barriers. In addition to a thematic analysis, an integrated view from the researcher as an experienced observer resulted in a validated conceptual framework. This framework provides a holistic set of factors that must be considered, and understood, from a corporate strategic perspective as being directly influential in achieving successful localisation of a subsidiary part of the business. It is found that four of the five objectives were met and objective five partially achieved which identified an opportunity for further research to investigate and develop weightings across the four localisation barrier themes to determine an optimised balance of cost, delivery, and local content to maintain the desired operational excellence in the oil and gas services contractor industry. The study appears to have a contribution to knowledge through the evolving conceptual framework of localisation and provides the first holistic view of both localisation drivers and barriers relevant to oil and gas services contractors. A methodological contribution is worth noting since the researcher acted as an experienced observer during the process of this research. No doubt, industrial experience of the research and his access to the senior management has been one of the key contributing factors to a successful completion of the study. Finally, one can argue that this study has made contribution to the policy makers who provided access to the researcher. The findings of this study will provide a better and clear understanding of localisation and its drivers and barriers.
2

Expression and subcellular localisation of poly(A)-binding proteins

Burgess, Hannah January 2010 (has links)
Poly(A)-binding proteins (PABPs) are important regulators of mRNA translation and stability. In mammals four cytoplasmic PABPs with a similar domain structure have been described - PABP1, tPABP, PABP4 and ePABP. The vast majority of research on PABP mechanism, function and sub-cellular localisation is however limited to PABP1 and little published work has explored the expression of PABP proteins. Here, I examine the tissue distribution of PABP1 and PABP4 in mouse and show that both proteins differ markedly in their expression at both the tissue and cellular level, contradicting the widespread perception that PABP1 is ubiquitously expressed. PABP4 is shown to be widely expressed though with an expression pattern distinct from PABP1, and thus may have a biological function in many tissues. I have shown that PABP4 associates with polysomes and described interactions between PABP4 and proteins important for PABP1-mediated translational activation suggesting that PABP4 plays a similar role in translational regulation. Translational inhibition is a common response to cell stress. Following certain cellular stresses e.g. arsenite, PABP1 localises to cytoplasmic stress granules, sites of mRNA storage. Here, I show that PABP4 is also a component of stress granules and have investigated the role of PABPs in stress granule formation. In contrast, I have shown that both PABP1 and PABP4 relocalise to the nucleus following UV irradiation in both human and mouse cell lines. In order to understand the how the UV-induced change in PABP localisation may be regulated, I have investigated the regulation of PABP nuclear export. I have found that accumulation of PABP proteins in the nucleus after UV coincides with an accumulation of poly(A)+ RNA, indicative of a block in mRNA export, an effect which has not been previously characterized. My working model is that nuclear export of PABPs may be dependent on mRNA export, inhibition of which leads to nuclear accumulation of PABPs after UV, which may in turn augment translational inhibition.
3

The relationship between adenovirus early region 1A protein and regulatory components of the 26S proteasome

Zhang, Xian January 2002 (has links)
No description available.
4

Aspects of localisation in off-diagonally disordered systems

Smyth, M. January 1987 (has links)
No description available.
5

Large-scale urban localisation with a pushbroom LIDAR

Baldwin, Ian Alan January 2013 (has links)
Truly autonomous operation for any field robot relies on a well-defined pyramid of technical competencies. Consider the case of an autonomous car – we require the vehicle to be able to perceive its environment through noisy sensors, robustly fuse this information into an accurate representation of the world, and use this representation to plan and execute complex tasks – all the while dealing with the uncertainties inherent in real world operation. Of fundamental importance to all these capabilities is localisation – we always need to know where we are, if we are to be able to plan where we are going (or how to get there). As road vehicles make the push towards becoming truly autonomous, the system’s ability to stay accurately localised over its operating lifetime is of crucial importance – this is the core issue of lifelong localisation. The goals in this thesis are threefold – to develop the hardware needed to reliably acquire data over large scales, to build a localisation framework that is robust enough to be used over the long–term, and to establish a method of adapting our framework when necessary such that we can accommodate the inevitable difficulties present when operating over city-scales. We begin by developing the physical means to make large-scale localisation achievable, and affordable. This takes the form of a stand-alone, rugged sensor payload – incorporating a number of sensing modalities – that can be deployed in either a mapping or localisation role. We then present a new technique for localisation in a prior map using an information theoretic framework. The core idea is to build a dense retrospective sensor history, which is then matched statistically within a prior map. The underlying idea is to leverage the persistent structure in the environment, and we show that by doing so, it is possible to stay localised over the course of many months and kilometres. The developed system relies on orthogonally-oriented ranging sensors, to infer both velocity and pose. However, operating in a complex, dynamic, setting (like a town centre) can often induce velocity errors, distorting our sensor history and resulting in localisation failure. The insight into dealing with this failure is to learn from sensor context – we learn a place-dependent sensor model and show that doing so is vital to prevent such failures. The integration of these three competencies gives us the means to make inex- pensive, lifelong localisation an achievable goal.
6

Etude du rôle des protéines de la famille PPR doublement adressées à la mitochondrie et au plaste dans l'édition de l'ARN chez Arabidopsis thaliana / Role of PPR proteins dually targeted to mitochondria and chloroplast in the RNA edition process in Arabidopsis thaliana.

Lopez Obando, Mauricio 06 May 2014 (has links)
La mitochondrie et le plaste sont des organites essentiels au sein de la cellule végétale. Les processus du métabolisme de l’ARN tels que la transcription, les modifications post-transcriptionnelles d'épissage et d’édition et la traduction des organites sont très similaires. Parmi les acteurs de ces processus, les protéines PentatricoPeptide Repeat (PPR) ont un rôle prépondérant. Dans ce travail de recherche, j’ai évalué, dans un premier temps, la double localisation des protéines PPR vers la mitochondrie et le chloroplaste chez Arabidopsis thaliana. La synthèse de l’ensemble des données ont permis d’établir que sur les 473 membres de la famille PPR chez A. thaliana, 9% ont une potentielle double localisation dans les deux organites. Un partie de ce travail de thèse, analyse et discute les implications évolutives et fonctionnelles au sein de cette classe de localisation. Afin de comprendre l’activité des protéines PPR dans les deux organites, j’ai focalisé mes analyses fonctionnelles sur quatre protéines PPR (OTP90, OTP91, OTP100 et DYW2) potentiellement impliquées dans le phénomène d’édition. Dans ce travail de thèse, j’ai pu mettre en évidence que les protéines OTP90 et DYW2 agissent sur l’édition des transcrits des organites et particulièrement que la protéine DYW2 participe dans l’édition des transcrits chloroplastiques comme aussi sur des transcrits mitochondriaux. Ainsi, les résultats de mon travail de recherche s’ajoutent aux récentes données, obtenues de par le monde, montrant que les protéines PPR peuvent avoir de rôles complexes bien influençant à la fois divers transcrits et/ou processus dans le métabolisme de l’ARN des organites. / Mitochondrial and plastid are essential organelles within the plant cell. The process of RNA metabolism such as transcription, post-transcriptional modifications as splicing and editing and translation are very similar in these organelles. Among the actors of these processes, the PentatricoPeptide Repeat (PPR) proteins have an important role. In this research, firstly, I assessed the dual localisation of PPR proteins to mitochondria and chloroplasts organelles in Arabidopsis thaliana. The synthesis of all the data, those produced during my thesis, those available in the literature and those contained in the proteomic databases have revealed that between the 473 members of the PPR family in A. thaliana, 9 % are potentially dually localaized in both organelles. A part of this thesis analyzes and discusses the evolutionary and functional implications of this class of localisation in the PPR family. In order to understand the activity of PPR proteins in both organelles, I focused my work in the functional analysis on four PPR proteins (OTP90, OTP91, OTP100 and DYW2 ) potentially involved in the editing process. Although functional characterization of these four proteins has not been fully completed, in this thesis, I was able to demonstrate that the OTP90 and DYW2 proteins act on editing of organelles transcripts and particularly I found that the DYW2 protein participates in the editing of chloroplast and mitochondrial transcripts. Thus, the results of my research are in concordance to recent data obtained by the world, showing that PPR proteins have complex roles influencing several transcripts and/or processes in the RNA metabolism of organelles.
7

Equivariant Cohomology and Localisation

Alonso i Fernández, Jaume January 2015 (has links)
Equivariant localisation is based on exploiting certain symmetries of some systems, generally represented by a non-free action of a Lie group on a manifold, to reduce the dimensionality of integral calculations that commonly appear in theoretical physics. In this work we present Cartan's model of equivariant cohomology in different scenarios, such as differential manifolds, symplectic manifolds or vector bundles and we reproduce the main corresponding localisation results.
8

Dynamique d'atomes dans des potentiels optiques : du chaos quantique au chaos quasi-classique / Dynamics of atoms in optical lattices : from quantum to quasi-classical chaos

Lepers, Maxence 03 April 2009 (has links)
Cette thèse présente des résultats théoriques sur le chaos dans les systèmes quantiques. Dans sa première partie, nous étudions la dynamique du rotateur pulsé. Ce système, qui est la référence pour l'étude du chaos quantique, présente un gel de la diffusion en impulsion, appelé localisation dynamique. Celle-ci est un phénomène purement quantique basé sur des interférences destructives. Comme tout phénomène d'interférence, la localisation dynamique est affectée par l'émission spontanée. Dans cette thèse, nous proposons une méthode basée sur la spectroscopie Raman, pour limiter l'impact de l'émission spontanée. Nous menons une étude analytique complète de la dynamique, en très bon accord avec nos simulations numériques. Du fait de sa périodicité temporelle, le rotateur pulsé présente aussi des résonances quantiques, qui sont l'analogue de l'effet Talbot optique. En décrivant ces résonances dans l'espace des positions, nous en donnons une image simple et intuitive, basée sur des notions classiques comme la force. Les condensats de Bose-Einstein ont ouvert la voie à l'obtention de phénomènes quantiques nouveaux. La non-linéarité de leur équation d'évolution permet notamment l'observation du chaos quasi-classique. Nous proposons ici une méthode pour le détecter, basée sur la mesure de la position moyenne du condensat. Cette méthode, dont la validité est confirmée par les exposants de Lyapunov du système, permet de distinguer sans équivoque les trajectoires chaotiques et régulières. / This thesis contains theoretical results about chaos in quantum systems. ln its first part, we study the dynamics of the quantum kicked rotor. This system, which is paradigmatic of quantum chaos, exhibits dynamical localization, a decay of diffusion in momentum space. The latter is a purely quantum phenomenon, as it is based on destructive interferences. As aIl interference effects, dynamical localization is affected by spontaneous emission. ln this manuscript, we propose a method to decrease the effect of spontaneous emission, by using Raman spectroscopy. We perform a full analytical study in very good agreement with our numerical simulations. As a consequence ofits temporal periodicity, the kicked rotor also exhibits quantum resonances, the analogy of the optical Talbot effect. By describing them in position space, we provide a simple and intuitive image of the resonances, based on classical notions like force. Bose-Einstein has enabled the study ofunprecedented quantum phenomena. ln particular, the nonlinearity of their evolution equation has made possible the observation of quasi-classical chaos. Here, we propose a method to detect chaos, by measuring the averaged position of the condensate. This method enables us to clearly distinguish chaotic and regular trajectories. Its validity is confirmed by the calculation of the system Lyapunov exponents.
9

La protéine Staufen humaine peut moduler la synthèse polypeptidique

Elvira, George January 1999 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
10

A comparison between vector algorithm and CRSS algorithm for indoor localization

Dama, Yousef A.S., Abd-Alhameed, Raed, Hammad, H., Zaid, R., Excell, Peter S. January 2014 (has links)
yes / In this paper a comparison between two indoor localization algorithms using received signal strength is utilized the vector algorithm and the Comparative Received Signal Strength algorithm. The comparison considered the effect of the radio map resolution, the number of access points, and the operating frequency on the accuracy of the localization process. The experiments were carried out using ray tracing software, measured values and MATLAB.

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