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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.
261

Teaching systems of linear equations in Sweden and China : what is made possible to learn? /

Häggström, Johan. January 2008 (has links)
Disputats, Göteborgs universitet, 2008. / Med litteraturhenvisninger.
262

Sequence stratigraphic characterisation of petroleum reservoirs in Block 11b/12b of the Southern Outeniqua Basin

Nformi, Emmanuel Nfor January 2011 (has links)
<p>The main purpose of this study was to identify and characterize the various sand prone depositional facies in the deepwater Southern Outeniqua Basin which generally tend to form during&nbsp / lowstand (marine regression) conditions producing progradational facies. It made use of sequence stratigraphy and turbidite facies models to predict the probable location of deepwater&nbsp / reservoirs in the undrilled Southern Outeniqua Basin using data from basin margin Pletmos Basin and the deepwater Southern Outeniqua Basin. Basin margin depositional packages were&nbsp / correlated in time and space with deepwater packages. It was an attempt at bridging the gap between process-related studies of sedimentary rocks and the more traditional economic geology&nbsp / f commercial deposits of petroleum using prevailing state-of-the-art in basin analysis. It enabled the most realistic reconstructions of genetic stratigraphy and offered the greatest&nbsp / application in exploration. Sequence stratigraphic analysis and interpretation of seismics, well logs, cores and biostratigraphic data was carried out providing a chronostratigraphic framework of the study area within which seismic facies analysis done. Nine (9) seismic lines that span the shallow/basin margin Pletmos basin into the undrilled deepwater Southern Outeniqua basin were analysed and interpreted and the relevant seismic geometries were captured. Four (4) turbidite depositional elements were identified from the seismic lines: channel, overbank deposits,&nbsp / haotic deposits and basin plain (basin floor fan) deposits. These were identified from the relevant seismic geometries (geometric attributes) observed on the 2D seismic lines. Thinning attributes, unconformity attributes and seismic facies attributes were observed from the seismic lines. This was preceded by basic structural analyses and interpretation of the&nbsp / seismic lines. according to the structural analysis and interpretation, deposition trended NW-SE and NNW-SSE as we go deepwater into the Southern Outeniqua basin. Well logs from six (6)&nbsp / of the interpreted wells indicated depositional channel fill as well as basin floor fans. This was identified in well Ga-V1 and Ga-S1 respectively. A bell and crescent shape gamma ray log&nbsp / signature was observed in well Ga-V1 indicating a fining up sequence as the channel was abandoned while an isolated massive mound-shape gamma ray log signature was observed in&nbsp / Ga-S1 indicating basin plain well-sorted sands. Core analyses and interpretation from two southern-most wells revealed three (3) facies which were derived based on Walker&lsquo / s 1978, turbidite&nbsp / facies. The observed facies were: sandstone, sand/shale and shale facies. Sequence stratigraphic characterisation of petroleum reservoirs in block 11b/12b of the Southern Outeniqua&nbsp / Basin. Cores of well Ga-V1 displayed fine-grained alternations of thin sandstone beds and shales belonging to the thin-bedded turbidite facies. This is typical of levees of the upper fan channel but&nbsp / could easily be confused with similar facies on the basin plain. According to Walker, 1978 such facies form under conditions of active fan progradation. Ga-S1 cores displayed not only classic&nbsp / turbidite facies where there was alternating sand and shale sections but showed thick uninterrupted sections of clean sands. This is typical of basin plain deposits. Only one well had&nbsp / biostratigraphic data though being very limited in content. This data revealed particular depth sections and stratigraphic sections as having medium to fast depositional rates. Such rates are&nbsp / characteristic of turbidite deposition from turbidity currents. This study as well as a complementary study by Carvajal et al., 2009 revealed that the Southern Outeniqua basin is a sand-prone&nbsp / basin with many progradational sequences in which tectonics and sediment supply rate have been significant factors (amongst others such as sea level change) in the formation of these&nbsp / deepwater sequences. In conclusion, the Southern Outeniqua basin was hereby seen as having a viable and unexplored petroleum system existing in this sand prone untested world class.</p>
263

A methodology for the robustness-based evaluation of systems-of-systems alternatives using regret analysis

Poole, Benjamin Hancock 01 July 2008 (has links)
After surveying the state-of-the-art in evaluation of alternatives in the defense acquisition process, a methodology for the evaluation of the robustness of systems-of-systems alternatives was proposed. In the methodology, robustness is defined as the integral of the alternative s regret over the likelihood-weighted plausible scenario space. Surrogate modeling techniques were used to overcome shortcomings associated with conventional regret analysis, including the discrete nature of scenario cases and static results. The new methodology, called Global Regret Analysis, was tested using an example problem based on the air campaign over Iraq in Operation Desert Storm. The results of the testing indicate that the methodology can provide a measure of the robustness of different system-of-systems alternatives against a wide range of possible scenarios. The methodology was then demonstrated on the US Air Force s persistent, precision strike mission. The demonstration showed the ability of Global Regret Analysis to overcome issues associated with using a single or other small number of scenarios to evaluate systems-of-systems alternatives. The methodology was then compared to a variety of existing methods and found to have strength for a wide range of evaluation applications. The possibility of applying Global Regret Analysis for military mission planning and opportunities for future work were also discussed.
264

Exploring the relationship of organisational culture to enterprise system success

Birbeck, Peter J. January 2008 (has links)
The doctoral research project is titled ‘An Exploration of the Relationship of Organisational Culture and Enterprise System Success and sought to address the research gap identified in the literature between organisational culture literature and Information System success literature. This is a research project which is funded by the Australian Research Council in conjunction with industry. The industry sponsors for this research were SAP AG, SAP USA and SAP ANZ. The research project adopted a multi-method research design, grounded in practice, in order to surface any reported relationship between Enterprise Systems Success (ESS) and Organisational Culture (OC). A critical part of the study was to identify who could report on this relationship. Partners in implementation include internal change managers, internal consultants, vendor consultants and implementation partner consultants. Representatives from each of these constituents were interviewed, covering a range of industry sectors and Enterprise Systems vendor organisations. The first phase of the research was to qualitatively assess the perception of these participants on the role of culture to Enterprise Systems Success. This phase used open, axial and selective coding of the responses obtained in a semi-structured interview. The next phase of the research was to gather quantitative measures of Organisational Culture and Enterprise Systems Success. The Organisational Culture Assessment Inventory (OCAI) of Cameron and Quinn was selected to gather quantitative data on Organisational Culture. The Enterprise Systems Success instrument of Gable, Sedera and Chan was selected to measure the perception of ESS because of its proven reliability and validity. Each of these data sets were then analysed to determine if an association existed between the cultures of organisations that achieved most success with the Enterprise System as opposed to the culture types reported of organisations that achieved the least success with the ES. These findings then assisted in the development of a model of interaction between OC and ESS. Finally, the relationship of OC to ESS was explored in a rich case study of one large firm, to determine if the consultant’s reported relationships could be identified in the subcultures of the organisation. The key findings of this study were: 1. There was a relationship reported between culture type and success types. The findings a-e below represent findings using the culture definitions from Cameron & Quinn’s culture instrument: a. clan cultures which emphasised the behaviours of development of others were related to reports of ESS b. hierarchical cultures which emphasised the behaviours of control and coordination were related to reports of ESS c. hierarchical cultures which were poor in the execution of control and coordination were related to reports of the least success with ES d. market cultures which emphasised (internal) competitiveness were strongly related to reports of least success with ES e. literature attributes of continuous improvement (CI), flexibility (F) and innovation (I), which are often described as antecedents to innovation success and are found in the culture type of adhocracy, were reported as strongly related to success of ES, but the culture type of adhocracy was not reported as being present in the quantitative data describing consultant experiences with enterprises which had implemented ES. 2. that the literature supported theoretical reasons for the above findings 3. that these patterns of association were found in the case study. The research supports the proposition that there is a relationship between Organisational Culture type and ESS. Certain culture types practice behaviours that correspond to reported necessary behaviours for innovation success and ESS, whilst other culture types practice behaviours that correspond to behaviours for failure of innovation and of ES failure. A model of and explanation for this relationship was proposed as a result of the findings. Future research is now required to empirically test this model.
265

SELinux policy management framework for HIS

Marin, Luis Franco January 2008 (has links)
Health Information Systems (HIS) make extensive use of Information and Communication Technologies (ICT). The use of ICT aids in improving the quality and efficiency of healthcare services by making healthcare information available at the point of care (Goldstein, Groen, Ponkshe, and Wine, 2007). The increasing availability of healthcare data presents security and privacy issues which have not yet been fully addressed (Liu, Caelli, May, and Croll, 2008a). Healthcare organisations have to comply with the security and privacy requirements stated in laws, regulations and ethical standards, while managing healthcare information. Protecting the security and privacy of healthcare information is a very complex task (Liu, May, Caelli and Croll, 2008b). In order to simplify the complexity of providing security and privacy in HIS, appropriate information security services and mechanisms have to be implemented. Solutions at the application layer have already been implemented in HIS such as those existing in healthcare web services (Weaver et al., 2003). In addition, Discretionary Access Control (DAC) is the most commonly implemented access control model to restrict access to resources at the OS layer (Liu, Caelli, May, Croll and Henricksen, 2007a). Nevertheless, the combination of application security mechanisms and DAC at the OS layer has been stated to be insufficient in satisfying security requirements in computer systems (Loscocco et al., 1998). This thesis investigates the feasibility of implementing Security Enhanced Linux (SELinux) to enforce a Role-Based Access Control (RBAC) policy to help protect resources at the Operating System (OS) layer. SELinux provides Mandatory Access Control (MAC) mechanisms at the OS layer. These mechanisms can contain the damage from compromised applications and restrict access to resources according to the security policy implemented. The main contribution of this research is to provide a modern framework to implement and manage SELinux in HIS. The proposed framework introduces SELinux Profiles to restrict access permissions over the system resources to authorised users. The feasibility of using SELinux profiles in HIS was demonstrated through the creation of a prototype, which was submitted to various attack scenarios. The prototype was also subjected to testing during emergency scenarios, where changes to the security policies had to be made on the spot. Attack scenarios were based on vulnerabilities common at the application layer. SELinux demonstrated that it could effectively contain attacks at the application layer and provide adequate flexibility during emergency situations. However, even with the use of current tools, the development of SELinux policies can be very complex. Further research has to be made in order to simplify the management of SELinux policies and access permissions. In addition, SELinux related technologies, such as the Policy Management Server by Tresys Technologies, need to be researched in order to provide solutions at different layers of protection.
266

Supporting strategic decisions for complex systems-of-systems: a syncretic approach

Staker, Roderick January 2006 (has links)
Complex Systems-of-Systems, which form the subject matter of the research presented here, may be considered to be systems that are constituted of several components, each of which could themself be regarded as being a complete system in its own right. These component systems are typically largely managed independently of one another. They each have their own intrinsic goals which they are capable of fulfilling autonomously. These goals are additional to any to which they might contribute as part of the overall System-of-Systems that is being investigated. Systems-of-Systems are epitomised by features such as the prevalence of complex webs of mutual interdependency amongst their component systems, the involvement of a broad diversity of stakeholders and the participation of a number of independent decision-makers, each of whom competes with the others for strictly limited resources. Furthermore, the components of Systems-of-Systems may often be found to be widely scattered across an extensive geographical region. Sometimes such systems may even span global distances. Complex Systems-of-Systems of such a nature would appear to be becoming ever more prevalent in the increasingly interconnected and ever shrinking world which is engendered, in particular, by the proliferation of modern information and communication technology. Systems-of-Systems may arise in both commercial and public sector contexts, hence commercial organisations and governments, alike, confront the daunting challenge of planning, establishing and maintaining novel systems of this type. However, it is to be anticipated that significant difficulties might be encountered in applying existing systems engineering methods, which were designed for dealing with far more monolithic types of system, to the treatment of Systems-of- Systems. Instead, the successful achievement of acceptable resolutions to the various Systems-of-Systems issues and conundrums with which the responsible planners can be expected to be confronted would appear to demand the application of sophisticated distributed decision aids, in order to alleviate the the intolerable burden which the decision-makers would otherwise be forced to endure. Such aids need to be able to take a genuinely fair and unbiased account of the interests of a multitude of stakeholders. At the same time, they must be able to satisfactorily accommodate the enforcement of a range of highly involved and intricate constraints upon the various alternative interventions which might potentially be contemplated. In order to underpin the development of decision aids of the kind demanded, it has been sought to establish some basic theoretical foundations for Systems-of-Systems. This body of theory has then been applied to the identification of the methods which might be most suitable for the treatment of Systems-of-Systems questions. Finally, some decision-support tools which are intended to facilitate the implementation of the methods that have been recommended have been described. Any attempt to dictate a single â??bestâ?? intervention to the decision-makers would generally be totally unacceptable. As a result, the objective which has been pursued has been to seek to filter out and identify a relatively sparing number of what would appear to be the most reasonable alternatives from some much more profuse range of possibilities. These may then be afforded more intensive scrutiny by the pertinent decision-makers.
267

The SGE framework discovering spatio-temporal patterns in biological systems with spiking neural networks (S), a genetic algorithm (G) and expert knowledge (E) /

Sichtig, Heike. January 2009 (has links)
Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Bioengineering, Biomedical Engineering, 2009. / Includes bibliographical references.
268

Defense co-production collaborative national defense /

Richardson, Robert R. January 1900 (has links)
Thesis (M.A.)--Naval Postgraduate School, 2005. / Title from title screen (viewed Apr. 16, 2008). Cites June 2003 GAO report GAO-03-695, "Contractors provide vital services to deployed forces but are not adequately addressed in DoD plans." "June 2005." The original document contains color images. "ADA435597"--URL. Includes bibliographical references (p. 91-96). Also issued in paper format.
269

Maintaining systems-of-systems fit-for-purpose : a technique exploiting material, energy and information source, sink and bearer analysis

Hinsley, Steven W. January 2017 (has links)
Across many domains, systems suppliers are challenged by the complexity of their systems and the speed at which their systems must be changed in order to meet the needs of customers or the societies which the systems support. Stakeholder needs are ever more complex: appearing, disappearing, changing and interacting faster than solutions able to address them can be instantiated. Similarly, the systems themselves continually change as a result of both external and internal influences, such as damage, changing environment, upgrades, reconfiguration, replacement, etc. In the event of situations unforeseen at design time, personnel (for example maintainers or operators) close to the point of employment may have to modify systems in response to the evolving situation, and to do this in a timely manner so that the system and/or System-of-Systems (SoS: a set of systems that have to interoperate) can achieve their aims. This research was motivated by the problem of designing-in re-configurability to the constituent systems of a SoS to enable the SoS and its systems to effectively and efficiently counter the effects of unforeseen events that adversely affect fitness-for purpose whilst operational. This research shows that a SoS does not achieve or maintain fitness-for-purpose because it cannot implement the correct, timely and complete transfer of Material, Energy and Information (MEI) between its constituents and with its external environment that is necessary to achieve a desired outcome; i.e. the purpose.
270

Motion synthesis for high degree-of-freedom robots in complex and changing environments

Yang, Yiming January 2018 (has links)
The use of robotics has recently seen significant growth in various domains such as unmanned ground/underwater/aerial vehicles, smart manufacturing, and humanoid robots. However, one of the most important and essential capabilities required for long term autonomy, which is the ability to operate robustly and safely in real-world environments, in contrast to industrial and laboratory setup is largely missing. Designing robots that can operate reliably and efficiently in cluttered and changing environments is non-trivial, especially for high degree-of-freedom (DoF) systems, i.e. robots with multiple actuators. On one hand, the dexterity offered by the kinematic redundancy allows the robot to perform dexterous manipulation tasks in complex environments, whereas on the other hand, such complex system also makes controlling and planning very challenging. To address such two interrelated problems, we exploit robot motion synthesis from three perspectives that feed into each other: end-pose planning, motion planning and motion adaptation. We propose several novel ideas in each of the three phases, using which we can efficiently synthesise dexterous manipulation motion for fixed-base robotic arms, mobile manipulators, as well as humanoid robots in cluttered and potentially changing environments. Collision-free inverse kinematics (IK), or so-called end-pose planning, a key prerequisite for other modules such as motion planning, is an important and yet unsolved problem in robotics. Such information is often assumed given, or manually provided in practice, which significantly limiting high-level autonomy. In our research, by using novel data pre-processing and encoding techniques, we are able to efficiently search for collision-free end-poses in challenging scenarios in the presence of uneven terrains. After having found the end-poses, the motion planning module can proceed. Although motion planning has been claimed as well studied, we find that existing algorithms are still unreliable for robust and safe operations in real-world applications, especially when the environment is cluttered and changing. We propose a novel resolution complete motion planning algorithm, namely the Hierarchical Dynamic Roadmap, that is able to generate collision-free motion trajectories for redundant robotic arms in extremely complicated environments where other methods would fail. While planning for fixed-base robotic arms is relatively less challenging, we also investigate into efficient motion planning algorithms for high DoF (30 - 40) humanoid robots, where an extra balance constraint needs to be taken into account. The result shows that our method is able to efficiently generate collision-free whole-body trajectories for different humanoid robots in complex environments, where other methods would require a much longer planning time. Both end-pose and motion planning algorithms compute solutions in static environments, and assume the environments stay static during execution. While human and most animals are incredibly good at handling environmental changes, the state-of-the-art robotics technology is far from being able to achieve such an ability. To address this issue, we propose a novel state space representation, the Distance Mesh space, in which the robot is able to remap the pre-planned motion in real-time and adapt to environmental changes during execution. By utilizing the proposed end-pose planning, motion planning and motion adaptation techniques, we obtain a robotic framework that significantly improves the level of autonomy. The proposed methods have been validated on various state-of-the-art robot platforms, such as UR5 (6-DoF fixed-base robotic arm), KUKA LWR (7-DoF fixed-base robotic arm), Baxter (14-DoF fixed-base bi-manual manipulator), Husky with Dual UR5 (15-DoF mobile bi-manual manipulator), PR2 (20-DoF mobile bi-manual manipulator), NASA Valkyrie (38-DoF humanoid) and many others, showing that our methods are truly applicable to solve high dimensional motion planning for practical problems.

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