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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.
191

The role and contribution of the Chief Technology Officer

van der Hoven, Christopher January 2011 (has links)
The Role and Contribution of the Chief Technology OfficerThe role of the Chief Technology Officer (CTO) came about because of new organisational demands on technology leaders in the 1980s. The initial research objective of this dissertation was to provide a clear scope of activities (a remit) for the CTO role. However, the analysis did not support a generic description for the role. Therefore, the approach taken explores CTO perspectives on technology management priorities when the technology context changes. There is limited literature on the role and contribution of the CTO per se. The resulting gap in the knowledge about the role is amplified by a wide variety of research methods and academic perspectives. From a theoretical point of view, the existing research tends to focus in isolation on the work being done, the working context or the worker (i.e. the CTO). There are studies that consider how the working context is changing, and studies that consider the work of the CTO, for example, the technology management priorities. There are still other studies that consider the attributes of the CTO. In this dissertation, these three perspectives - the working context, the work and the worker - are investigated in an integrated way using a data collection technique called 'personal role mapping' that is based on cognitive mapping. The 'personal role mapping' approach has been developed as part of this work. The evidence collected and analysed shows that the role of the CTO is highly idiosyncratic. This is because the CTO role changes as the organisation adapts in order to compete. Also, the role differs from one industry to another and between organisations within the same industry. To help deal with these variations, a CTO/Context Framework has been derived for use in conjunction with 'technology transition points'. The CTO/Context Framework has 20 sub-elements that support 6 primary elements including, 'technology management infrastructure', 'technology entry/exit points', 'technology business case & funding', 'operational improvement', 'people management' and 'technology business model & strategy'. The CTO can review each element with related sub-elements in anticipation or at the point of a 'technology transition'. This model for the CTO role is proposed as an alternative to a generic 'job description' (remit) for the CTO role. It is intended to be used as a platform for planning and decision-making. Together, the framework and the research approach for mapping an individual's role are offered as a unique contribution to knowledge.
192

Systém kritických bodů v cukrárenské výrobě / The critical points in the confectionery manufacturing

Feriová, Lucie January 2004 (has links)
The aim of thesis is a system of critical points in food production, especially in the production of confectionery products. The system is based on the ability of manufacturers to establish the critical aspects of the production of safe food, allows to systematically identify hazards and assess the probability of its occurrence during production. Danger primarily as a substance in food, which could result in adverse health effects for consumers. And subsequently helps to improve the effectiveness of controls. This concept of control techniques is apparented from the national and European legislative requirements, which are listed in the first theoretical part of this thesis. They are designed to better acquaint themselves with the general requirements that are placed on food manufacturers. With the entry into the European Union is integrated European legislation, national legislation incorporated in European policy and legal requirements are taken into national legislation the second part introduces the principles and procedures of the system of critical points. Many manufacturing processes involve multi-process from producing raw materials for the finished product. Correct, complete, and introduced the study of critical points identified by the system and regulate the factors that directly affect the safety of products. Identification and monitoring of critical points is more cost effective than the method of quality assurance inspection and testing of finished product. Records and documentation are the perfect evidence that all measures have been taken and were given the duty of care to prevent problems. In the final section is a common procedure for a system of critical points compared with an established system for a particular product. The specific products will be demonstrated readiness and capacity of the undertaking to establish a system for all products or product groups, which will subsequently be evaluated. The purpose of thesis is carefully and thoroughly analyze the system by the critical points in the manufacture of confectionery, but prove that we are able to prepare for the strict legal conditions and the hard and fierce competition. This development does not stop or avoid it, have no other than to respond promptly to these developments and to adapt in order to produce the desired changes brought about by the success and to our food industry was at a level as we wish, but also as your own work and creativity deserve. Not in vain proverb holds that "Happiness wishes prepared.
193

Průmyslový park Karviná - zhodnocení konkurenceschopnosti podniku a návrh strategického rozvoje / Industrial estate Karviná - competitive advantage of the company and proposal of their strategic progress

Tomanová, Eva January 2009 (has links)
The aim of diploma thesis is analysis of the company and Industrial site Průmyslový Park Karviná, to introduce organizational structure of the company, licence and posibilities of PPK. To try describe the structure of tenants, abstract of basic results and findings of the strategic analysys. Proposal of advancements of the site and try to find some strategic points in decision making.
194

Reconstruction robuste de formes à partir de données imparfaites / Robust shape reconstruction from defect-laden data

Giraudot, Simon 22 May 2015 (has links)
Au cours des vingt dernières années, de nombreux algorithmes de reconstruction de surface ont été développés. Néanmoins, des données additionnelles telles que les normales orientées sont souvent requises et la robustesse aux données imparfaites est encore un vrai défi. Dans cette thèse, nous traitons de nuages de points non-orientés et imparfaits, et proposons deux nouvelles méthodes gérant deux différents types de surfaces. La première méthode, adaptée au bruit, s'applique aux surfaces lisses et fermées. Elle prend en entrée un nuage de points avec du bruit variable et des données aberrantes, et comporte trois grandes étapes. Premièrement, en supposant que la surface est lisse et de dimension connue, nous calculons une fonction distance adaptée au bruit. Puis nous estimons le signe et l'incertitude de la fonction sur un ensemble de points-sources, en minimisant une énergie quadratique exprimée sur les arêtes d'un graphe uniforme aléatoire. Enfin, nous calculons une fonction implicite signée par une approche dite « random walker » avec des contraintes molles choisies aux points-sources de faible incertitude. La seconde méthode génère des surfaces planaires par morceaux, potentiellement non-variétés, représentées par des maillages triangulaires simples. En faisant croitre des primitives planaires convexes sous une erreur de Hausdorff bornée, nous déduisons à la fois la surface et sa connectivité et générons un complexe simplicial qui représente efficacement les grandes régions planaires, les petits éléments et les bords. La convexité des primitives est essentielle pour la robustesse et l'efficacité de notre approche. / Over the last two decades, a high number of reliable algorithms for surface reconstruction from point clouds has been developed. However, they often require additional attributes such as normals or visibility, and robustness to defect-laden data is often achieved through strong assumptions and remains a scientific challenge. In this thesis we focus on defect-laden, unoriented point clouds and contribute two new reconstruction methods designed for two specific classes of output surfaces. The first method is noise-adaptive and specialized to smooth, closed shapes. It takes as input a point cloud with variable noise and outliers, and comprises three main steps. First, we compute a novel noise-adaptive distance function to the inferred shape, which relies on the assumption that this shape is a smooth submanifold of known dimension. Second, we estimate the sign and confidence of the function at a set of seed points, through minimizing a quadratic energy expressed on the edges of a uniform random graph. Third, we compute a signed implicit function through a random walker approach with soft constraints chosen as the most confident seed points. The second method generates piecewise-planar surfaces, possibly non-manifold, represented by low complexity triangle surface meshes. Through multiscale region growing of Hausdorff-error-bounded convex planar primitives, we infer both shape and connectivity of the input and generate a simplicial complex that efficiently captures large flat regions as well as small features and boundaries. Imposing convexity of primitives is shown to be crucial to both the robustness and efficacy of our approach.
195

Molecular beam epitaxial growth and characterization of GaAs and GaAsBi based semiconductor devices

Mahtab, Mahsa 22 December 2020 (has links)
GaAs(1-x)Bi(x) (x = 0 to 17%) optical properties were investigated by spectroscopic ellipsometry (in energy ranges of 0.37–9.0 eV). Optical features in the dielectric function, known as the critical points, were distinguished and modeled using standard analytic line shapes. The energy dependence of the critical points energies was thoroughly investigated as a function of Bi content and thin film strain. Critical points analysis in the Brillion zone showed that the top of the valence band is most strongly dependent on Bi content compared to other parts of the band structure. In addition, an interesting new critical point was observed that is attributed to alternative allowed optical transitions made possible by changes to the top of the valence band caused by resonant interactions with Bi orbitals. Several of the critical points were extrapolated to 100% Bi and showed reasonable agreement with the calculated band structure of GaBi. GaAs(1-x)Bi(x) (x= 03, 0.7 and 1.1%) based p+/n and n+/p heterostructure photovoltaic performance was characterized through IV and CV measurement. By introduction of Bi into GaAs, a non-zero EQE below the GaAs band edge energy was observed while the highest efficiency was obtained by ~ 0.7% Bi incorporation. EQE spectrum was modeled to find the minority carrier diffusion lengths of ~ Ln = 1600 and Lp = 140 nm for p-doped and n-doped GaAs92Bi08 in the doping profile of 10^15 - 10^16 cm^-3. Analysis of the CV measurement confirmed the background n-doping effect of Bi atom and the essential role of the cap layer to reduce multi-level recombination mechanisms at the cell edge to improve ideality factor. Low temperature grown GaAs was optimized to be used as photoconductive antenna in THz time-domain spectroscopy setup. The As content was investigated to optimize photo-carrier generation using 1550 nm laser excitation while maintaining high mobility and resistivity required for optical switching. A barrier layer of AlAs was added below the LT-GaAs to limit carrier diffusion into the GaAs substrate. Moreover, LT-GaAs layer thickness and post-growth annealing condition was optimized. The optimized structure (2-µm LT-GaAs on 60-nm AlAs, under As2:Ga BEP of ~7, annealed at 550°C for 1 minute) outperformed a commercial InGaAs antenna by a factor of 15 with 4.5 THz bandwidth and 75 dB signal-to-noise ratio at 1550 nm wavelength. / Graduate
196

Melt Initiation and Propagation in Polycrystalline Thin Films

Pan, Wenkai January 2021 (has links)
Melting of elemental solids can be identified and appreciated as a particularly simple example of discontinuous phase transitions involving condensed phases. Motivated, on the one hand, by the need to improve the microstructural quality of laser-crystallized columnar-grained polycrystalline Si films for manufacturing advanced AMOLED displays and, on the other hand, to investigate the fundamental details associated with phase transformations transpiring in condensed systems, this thesis examines the initiation and evolution of melting in polycrystalline thin films. Distilling the essence of the classical nucleation theory and extending its description to address more general cases of phase initiation and evolution, a general thermodynamic method based on capillarity effect is developed and applied to determine the shape of solid/liquid interfaces that are in mechanical equilibrium. We first explicitly identify and build our analysis based on how the shape of solid/liquid interfaces must comply with the contact angle conditions at the junctions and also the property of constant mean curvature. Bi-crystal and tri-crystal models are presented to capture the microstructural features such as junctions and vertices of interfaces in polycrystalline thin films. At each of the potential melt initiating sites, the parameter space of contact angles is divided into domains depending on the shape of the solid/liquid interface that can be established in mechanical equilibrium. Melting initiation mechanisms are subsequently determined based on the permissible shape for each domain. This analysis is further extended to the edges and corners of embedded cubic crystals (with nonidentical contact angles at different faces). Secondly, in order to facilitate the thermodynamic analysis of the melting initiation and interface propagation, we extend our curvature-evolution-centric method to identify and develop what we consider as the central function for discontinuous phase transitions. Specifically, starting with a local governing condition, identifies and builds on two curvatures: ρ^E (𝑉) and ρ* (𝑇). ρ^E (𝑉) captures the evolution of the mean curvature of the solid/liquid interface as a function of liquid volume for the case in which the mechanical equilibrium condition is satisfied, whereas ρ* (𝑇) incorporates the temperature effect on the difference between the volumetric free energy of solid and liquid phases using the corresponding equilibrium mean curvature. We define and identify the interface driving stress function ƒ(𝑉,𝑇)=∂𝐺/∂𝑉=σ(ρ^E (𝑉)-ρ* (𝑇)) of the phase transition as being an important fundamental quantity, which can be directly derived by taking the difference of the two curvature terms. In contrast to the conventional analysis that requires integration of volumetric and interfacial free energy terms over various geometric domains to derive the total free energy as a function of volume for a given temperature, this formation completely disentangles geometry from the thermodynamic aspects of the phase transition and allows them to be treated separately. In addition to providing essentially all relevant thermodynamic information about the phase initiation and evolution, the above method readily permits the use of powerful general-purpose numerical tools to calculate the potentially complex geometry of the solid/liquid and other interfaces and obtain ρ^E (𝑉) directly as the output. Plotting the ρ^E (𝑉) function together with the temperature-dependent iso-curvature line, ρ* (𝑇), unveils the critical thermodynamic information regarding the melting transition at the temperature, such as whether equilibrium points exist, the number of equilibrium points, their stability, and their corresponding volumes. The change of free energy as a function of liquid volume can be derived through integration of the interface driving stress function. The velocity of the solid/liquid interface is simply proportional to the interface driving stress function. The application of this method is demonstrated in both shape-preserving (which we term as isomorphic) and shape-changing (which we term as non-isomorphic) examples. The analysis and findings presented in this thesis are relevant and useful for understanding discontinuous phase transitions, in general, and can be particularly so for small, confined, and embedded systems that are increasingly being utilized in modern technologies.
197

Tvorba 3D modelu hradu Kumburk / Creation of 3D model of castle Kumburk

Andrle, Jan January 2014 (has links)
The subject of this thesis is the creation of documentation castle ruins Kumburk form of digital 3D model by photogrammetrical method using optical correlation. Text section describes the way of control establishing, measuring control points and photographic work. Furthermore, the text is dedicated to creating the 3D model itself, and testing its accuracy. Appendix contains the control documentation, testing the accuracy of the model and the 3D model in various formats.
198

Analytic properties of the Jost functions

Mvondo-She, Yannick January 2013 (has links)
Recently, was developed a new theory of the Jost function, within which, it was split in two terms involving on one side, singlevalued analytic functions of the energy, and on the other, factors responsible for the existence of the branching-points. For the single-valued part of the Jost function, a procedure for the powerseries expansion around an arbitrary point on the energy plane was suggested. However, this theory lacks a rigorous proof that these parts are entire functions of the energy. It also gives an intuitive (not rigorous) derivation of the domain where they are entire. In the present study, we ll this gap by using a method derived from the method of successive approximations. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Physics / unrestricted
199

2-D Melting in Excimer-Laser Irradiated Polycrystalline Silicon Films

Wong, Vernon January 2021 (has links)
This thesis examines the excimer-laser-induced melting of ELA-prepared silicon films using in situ transient reflectance and transmission analysis. The results clearly show that these polycrystalline films, which consist of columnar grains in contact with SiO₂, can melt in a largely and remarkably 2-D manner. Based on the presently and previously obtained experimental results, as well as considering the thermal, thermodynamic, and kinetic aspects of the melting-transition-relevant details, we suggest a model that consists of grain-boundary-initiated melting, followed by lateral melting proceeding into the transiently superheated interior of the grains. Additional experiments are performed which demonstrate how this 2-D melting behavior at least stems intrinsically from the presence in the material of melt-prone grain boundaries and superheating-permitting Si/SiO₂ interfaces. Next, the phase and temperature evolutions of the irradiated films are investigated using a numerical simulation program, which incorporates key material, thermodynamic, and kinetic parameters. We find that the center portion of the grains during (partial) melting (1) corresponds to, especially at the SiO₂-passivated surface, the hottest regions of the films during rapid heating, and (2) remains entirely solid throughout the thickness of the film, as the maximum temperature sustained in these unmelted solids remains well below the superheating limit of silicon at the Si/SiO₂ interface. Lastly, we discuss, and substantiate with results obtained from numerical simulations, the role that the manifested dimensionality of melting plays in dictating the efficiency with which the ELA crystallization technique can generate microstructurally uniform polycrystalline materials. The current discovery regarding the 2-D nature of melting should be recognized and appreciated as a critical process-enabling element for ELA, as the scenario permits microstructure evolution of the grains to take place in an effective manner.
200

The Development and Effectiveness of Malware Vaccination : An Experiment

Ädel, Lukas, Eliasson, Oskar January 2020 (has links)
Background. The main problem that our master thesis is trying to reduce is malware infection. One method that can be used to accomplish this goal is based on the fact that most malware does not want to get caught by security programs and are actively trying to avoid them. To not get caught malware can check for the existence of security-related programs and artifacts before executing malicious code and depending on what they find, they will evaluate if the computer is worth infecting. The idea is that by identifying these checks we could "vaccinate" a system with data-points that trigger these checks and trick the malware into believing that a system is protected and skip it. Objectives. This thesis will research common malware evasion techniques to find what data-points malware avoids and develop a vaccine with the found data-points. To test the effectiveness of the vaccine an experiment will be conducted where malware will be executed on different systems to observe their behavior. Methods. The vaccine concept will be tested by gathering data-points with a background review of related works and performing an experiment. In the experiment a virtual machine without protective measures is used as a baseline which can be compared to a virtual machine with the vaccine. It is also interesting to see how a vaccine compares to an antivirus solution and how / if it would cooperate with an antivirus solution, so two more virtual machines are added to the experiment, one with just an antivirus software installed, and a second one with antivirus installed plus the vaccine. On these four systems, a set of malware will be executed and their behavior and activity (Windows API calls) will also be measured and compared. Results. This experiment showed that our vaccine was effective in reducing malware behavior, 70% of the malware did reduce their activity when exposed to the vaccine compared to the baseline. The results also indicate that the vaccine was effective in cooperation with an antivirus program, 85% of the malware did reduce their activity on this virtual machine compared to the baseline. Conclusions. From the results, we can conclude that of our created systems the system that reduced the most malware activity was the system with antivirus plus vaccine. This shows that vaccination can be a viable option for researchers to further study.

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