Porphyromonas gingivalis is a major etiological agent that is responsible for the cause and progression of periodontal diseases. The bacterium is exposed to various environmental conditions and oxidative stress conditions while it is in the oral cavity. So, P. gingivalis should have an efficient regulatory system in order to adjust and survive in the oral cavity. But little is known about the regulatory mechanisms that help the bacteria to survive in the oral cavity. So, it is essential to understand and characterize these regulatory mechanisms. The response and adaptation of P. gingivalis to environmental stress conditions occur at the level of transcription which involves the alternative sigma factors. Extracytoplasmic function (ECF) sigma factors are the largest group of alternative sigma factors that play a major role in bacterial response to environmental stress conditions. Here we characterize the σ-70 factor, SigH and SigG, the extracytoplasmic function sigma factors encoded in P. gingivalis genome. Our results show that the expression of SigH is upregulated when P. gingivalis is grown in the presence of oxygen. However, there is no change in the expression of SigG when grown in the presence of oxygen. Furthermore several genes involved in oxidative stress protection such as sod, trx, tpx, ftn, feOB and the hemin uptake locus, hmu, are downregulated in the mutant deficient in SigH designated as V2948. Our RNA-seq analysis of SigG showed that there is no change in the regulation of genes involved in oxidative stress protection and metal homeostasis in SigG deficient mutant designated as V3085. Our survival studies showed that both SigH and SigG are essential for P. gingivalis to grow in host cells. Collectively our studies demonstrate that SigH is a positive regulator of gene expression required for survival of the bacterium in the presence of oxygen and oxidative stress, hemin uptake and virulence. However our studies show that SigG is essential for the bacteria to grow in host cells and hence helps in the virulence of P. gingivalis.

El presente estudio tiene como objetivo disminuir la variabilidad de tiempo en el proceso de afiliación de comercios al servicio de comercio electrónico de una empresa del rubro de medios de pago empleando la metodología DMAIC. El estudio se inicia con el desarrollo del marco teórico que sirve como fundamento para el desarrollo de la metodología. Seguidamente, se realiza una descripción de la organización, su infraestructura, recursos y el proceso de afiliación general. Asimismo, se realiza un diagnóstico al proceso de afiliación general y se selecciona el proceso de afiliación al servicio de comercio electrónico como el más crítico. Luego, se desarrollan las etapas de definición, medición, análisis, propuestas de mejora y control de las mismas en el proceso seleccionado. En la etapa de definición se identifican los principales problemas en el proceso de afiliación que resultan ser los tiempos de las variables: tiempo generación de código, tiempo de integración, tiempo de gestión de cobranza y tiempo de capacitación y habilitación de comercio. Para ello, fue necesario describir el proceso, conocer la voz del cliente y priorizar los principales problemas del proceso. En la etapa de medición se describe el plan de muestreo para la toma de datos, se seleccionan las variables críticas del proceso y se realiza las mediciones de capacidad de proceso. En la etapa de análisis se determinan y analizan las causas que originan los tiempos altos en el proceso de afiliación. Además, de acuerdo al resultado del diseño de experimentos desarrollado, se determinaron los factores relevantes para cada una de las variables de respuesta. En la etapa de mejora se diseñan las propuestas de mejora en base a los resultados obtenidos en las etapas previas. Se establecen los valores adecuados de los factores identificados como relevantes, según los resultados del diseño de experimentos, para optimizar el proceso de afiliación. Se propone la implementación de herramientas de mejora como 7 desperdicios o MUDA, programa 5´S, un plan de capacitación y estandarización del proceso de afiliación. En la etapa de control de las mejoras se propone el uso de tablas de control y herramientas Poka Yoke desarrolladas bajo la modalidad de semaforización en el sistema de atención al cliente. Finalmente, se realiza una evaluación técnica y económica de las propuestas de mejoras, obteniendo como resultado la viabilidad económica del proyecto. / Tesis

El presente trabajo nace por la necesidad de reducir el scrap en una planta de producción de frascos para el sector cosmético, farmacéutico y alimenticio; específicamente el estudio es realizado en las cuatro líneas de polietileno con que cuenta la planta de producción. Previo al trabajo planteado se analizaron todos los indicadores utilizados en la planta de producción para evaluar y elegir el proyecto que resulte más rentable y siempre teniendo en cuenta la voz del cliente y los objetivos de la empresa. Según data obtenida, en el año 2014 el scrap producido fue del 21%, existiendo una gran brecha con el objetivo del 5%, por lo que se recomienda el uso de la metodología Six Sigma por sus casos de éxito conocidos en la reducción del scrap. Debido a que en la empresa nunca se ha desarrollado la metodología Six Sigma, se realizaron con el apoyo de la gerencia de producción, reuniones con algunos supervisores y operarios de las líneas de polietileno para darles un alcance de los beneficios de la metodología. Gracias a su apoyo se obtuvo información valiosa para el desarrollo del presente trabajo así como también para el cumplimiento de las mejoras propuestas como parte de un plan piloto en el desarrollo del DMAIC en la línea 1 con ayuda de herramientas como el Mapa de procesos, FMEA, Paretto 80-20, diagrama causa-efecto así como también de herramientas estadísticas. Luego de desarrollar las mejoras, se tomaron de datos para un nuevo proceso de análisis, se desarrollaron pruebas de hipótesis; encontrándose que en dos meses se obtuvo una mejora importante del 5%, comprobándose lo efectivo de la metodología para la reducción del scrap. El VAN y el TIR en la evaluación económica realizada nos arrojan resultados positivos de ganancia y rentabilidad que sustentan la ejecución del proyecto. Este trabajo presenta los pasos a seguir para que la empresa pueda implantar la metodología Six Sigma en sus líneas de producción de polietileno. / ABSTRACT This work is developed from the need to reduce the scrap in a production plant for cosmetic, pharmaceutical and food sector; specifically the study is conducted in the four lines of polyethylene available to the plant. Prior to the proposed work all the indicators used in the production plant were evaluate and the most profitable project was choose. I was also taken into account the voice of the customer and the company goals. According to data obtained in 2014 the scrap produced was 21%, with a big gap to the target of 5%, so the use of Six Sigma for its known cases of success in reducing the scrap is recommended . Because the company has never developed the Six Sigma methodology, were meetings with the support of production management, with some supervisors and operators of polyethylene lines to give them a range of benefits of the methodology. Thanks to your support valuable information for the development of this work as well as for compliance with the proposed improvements as part of a pilot plan in the development of DMAIC on line 1 using tools like process map, FMEA , Paretto 80-20, cause-effect diagram as well as statistical tools. After developing improvements, data were taken for a new process of analysis, hypothesis testing were developed; It is meeting in two months a significant improvement of 5% was obtained, proving how effective methodology for reducing scrap. VAN and TIR in the economic assessment throw us gain positive results and profitability that support project implementation. This paper presents the steps for the company to implement Six Sigma in its polyethylene production lines. / Tesis

The Extended Kalman Filter (EKF), Unscented Kalman Filter (UKF) and Ensemble Kalman Filter (EnKF) are commonly implemented practical solutions for solving nonlinear state space estimation problems; all based on the linear state space estimator, the Kalman Filter. Often, the UKF and EnKF are cited as a superior methods to the EKF with respect to error-based performance criteria. The UKF in turn has the advantage over the EnKF of smaller computational complexity. In practice however the UKF often fails to live up to this expectation, with performance which does not surpass the EKF and estimates which are not as robust as the EnKF. This work explores the geometry of alternative sigma point sets, which form the basis of the UKF, contributing several new sets along with novel methods used to generate them. In particular, completely novel systems of sigma points that preserve higher order statistical moments are found and evaluated. Additionally a new method for scaling and problem specific tuning of sigma point sets is introduced as well as a discussion of why this is necessary, and a new way of thinking about UKF systems in relation to the other two Kalman Filter methods. An Iterated UKF method is also introduced, similar to the smoothing iterates developed previously for the EKF. The performance of all of these methods is demonstrated using problem exemplars with the improvement of the contributed methods highlighted.

Requirements for increased operating efficiencies mean that future generations of aero-engines will need to operate at temperatures beyond the capabilities of current nickel-base superalloys. As a result, new alloy compositions for turbine disc applications are being developed. Optimising these alloy compositions requires balancing directly competing requirements. Increased Cr contents are needed to provide environmental resistance and increased concentrations of other refractory metals to improve solid solution strengthening. However, these elements compromise the alloyâs long-term microstructural stability by promoting the formation of topologically close-packed (TCP) phases, which are deleterious to alloy performance. High $\gamma^\prime$ volume fractions, which are needed to provide high-temperature strength, exacerbate the problem by increasing the concentration of these elements in the $\gamma$ phase. Therefore, an understanding of TCP formation and the compositional limits of stability is vital in the design of new alloys. This thesis presents a combination of fundamental studies of TCP phase formation in model alloys and microstructural assessment of the thermal stability of developmental alloy compositions. Knowledge of the effect of individual elements on thermal stability is important to enable the development of optimised alloy compositions. As a result, the first fundamental study investigated the effect of Co content on thermal stability. An unexpected transition in $\sigma$ precipitation behaviour after 500 hours at 800°C was observed between 12 and 16 at.\% Co. It is proposed that this behaviour may be due to the effect of Co on the $\gamma$/$\gamma^\prime$ partitioning behaviour of other elements. Preliminary results from further fundamental studies investigating the effect of the Mo/W ratio and B content on thermal stability are also presented. Decreasing the Mo/W ratio was found to reduce the quantity of $\sigma$ precipitation and promote the precipitation of a W-rich phase. B additions were found to promote the precipitation of the M$_3$B$_2$ phase. Thermodynamic predictions are frequently used to inform alloy design as an alternative to time-consuming and costly experiments. However, the accuracy of solvus temperature predictions for TCP phases has not been thoroughly considered. In this work, it was found that differential scanning calorimetry could be used as a means of measuring $\sigma$ solvus temperature in a series of alloys designed to be sufficiently unstable with respect to $\sigma$ precipitation. Comparison of experimental results with thermodynamic solvus temperature predictions revealed a significant underprediction of the $\sigma$ solvus temperatures for all of the studied alloys. This can inform our use of such predictions during alloy design. The ability to quantify the amount of TCP precipitation that occurs is extremely important when assessing the thermal stability of alloys. A new method was applied to the problem of TCP quantification, involving synchrotron X-ray diffraction of solid aged samples. This was an attempt to avoid some of the problems identified with the commonly used quantification method, which involves electrolytic extraction of minor phases, and assess the accuracy of the results produced by this method. Samples of a currently used commercial alloy, RR1000, were investigated following ageing for up to 5000 hours at 800°C, revealing the evolution of phases at this temperature. The presence of extremely low quantities of minor phases was successfully detected in the solid samples using this method. However, these quantities were too low for this to be a reliable method of quantification for commercial alloys. In parallel with these fundamental and technique-based studies, the thermal stability of a number of candidate alloys, which were developed during the design of a next-generation disc alloy by Rolls-Royce, was assessed. The alloys were characterised following a variety of thermal exposure temperatures and durations, which were determined by industrial needs at the time. Various minor phases were identified depending on the alloy compositions, including the TCP phases, $\sigma$ and $\mu$, as well as MC and M$_{23}$C$_6$ carbides and M$_3$B$_2$ borides.

Dans cette thèse on étudie certaines constructions géométriques qui apparaissent naturellement dans le contexte des modèles sigma, leur jaugeage et supersymétrisation. La thèse comprend trois parties. La première partie (chapitres 1 et 2) contient des faits issus de la géométrie différentielle classique et de la géométrie graduée nécessaires pour comprendre les résultats clés de la thèse. On survole la géométrie liée aux variétés de Poisson et variétés symplectiques. On généralise ces notions aux variétés de Dirac et variétés n-plectiques, et établit leur liens avec les algebroïdes de Courant. Le langage principal utilisé dans la thèse pour la description mathématique des modèles sigma – c'est la géométrie graduée – on définit donc des bases de calcul sur les supervariétés et variétés graduées ainsi que les notions des Q-structures et des variétés multigraduées. La deuxième partie (chapitres 3 et 4) a pour but d’interpréter géométriquement l'invariance de jauge de certains modèles sigma. On établit la relation entre les symétries de modèle sigma de Dirac, et comme cas particulier de modèle sigma de Poisson (tordu), avec les sous-algèbres des sections d'algebroïde de Courant. On généralise la notion de cohomologie équivariante, ce qui permet d'obtenir les modèles sigma avec le groupe des symétries prescrit, en particulier on construit les groupes nécessaires pour les modèles sigma mentionnés. La troisième partie (chapitre 5) adresse l'extension graduée des modèles sigma (comme en supersymétrisation). Ceci est en fait lié auxstructures géométriques qui peuvent être définies sur l'espace des applications entre les variétés multigraduées / In this thesis we study some geometric constructions appearing naturally in the context of sigma models, their gauging and supersymmetrization. The thesis consists of three parts. The first part (chapters 1 and 2) contains facts coming from classical differential geometry and graded geometry, they are needed to understand the main results of the thesis. We review the geometric constructions related to Poisson and symplectic manifolds. We generalize these notions to Dirac and n-plectic manifolds and establish the links with Courant algebroids. The main language used in the thesis for mathematical description of the sigma models is the graded geometry - we thus define the basis of calculus on supermanifolds and graded manifolds, as well as describe the notions of Q-structures and multigraded manifolds. The main goal of the second part (chapters 3 and 4) is to interpret geometrically the gauge invariance of some sigma models. We establish the relation of the symmetries of the Dirac sigma model, and as a particular case of the (twisted) Poisson sigma model, with the subalgebra of sections of Courant algebroid. We generalize the notion of equivariant cohomology, that permits to recover the sigma models with a prescribed group of gauge symmetries. In particular we construct the necessary groups for the mentioned sigma models. The third part (chapter 5) addresses the graded extension of the sigma models (like in supersymmetrization). It is in fact related to the geometric structures that can be defined on the space of maps between multigraded manifolds.

Med ett klart system för hur en produktion skall fungera, i form av standardiserade processer, går det att minska de slöserierna som uppkommer i form av material och onödiga rörelser. Göteborgs kex är ett företag som är intresserade av att kunna minska sina slöserier och arbeta med förbättringsarbete för att kunna bli mer effektivare i sin produktion.Göteborgs kex är Skandinaviens ledande tillverkare av kex och ingår i norska Orkla-koncernen, som den största distributören av märkesvaror till dagligvaruhandel i Norden.Det problem som de har är ett område som heter Blå hallen. Mycket material byggs upp i form av lager inne i blå hallen och detta blir en fara för de som arbetar där då deras hälsa, arbetsmiljö och säkerhet påverkas. Avsikten med detta examensarbete är att utforska detta område och komma med förslag på hur de kan förbättra och effektivisera sina processer där. Målet är att minska lagerhanteringen och förbättra arbetsmiljön för de som arbetar där.Processförbättringar görs genom att kartlägga den nuvarande processen och därefter eliminera onödiga aktiviteter. Dock är processförbättringar mycket krävande av ledningen och deras engagemang i produktionen. Processhantering görs i form av implementering av olika roller och ansvar med betoning på Sex sigma och Kaizen. Detta lägger grunden för en kontinuerligt förbättrande process där onödiga slöserier och kostnader reduceras.En processkartläggning kommer att göras för att få en överblick på de nuvarande processerna för att sedan komma med förslag till förbättringar som ska minimera de problem som uppstår och eliminera onödiga aktiviteter. Genom kvalitativa och kvantitativa undersökningsmetoder, där observationer och intervjuer med olika områdesansvariga personer och kurslitteratur så har olika förslag som läggs fram i arbetet bearbetats.Förslagen grundar sig på fakta man samlat in och den processkartläggning som gjordes. Processkartläggningen gav en överskådlig blick på kommunikationsprocessen där det som skulle förmedlas från ledningen till produktionen var vagt. Vidare studier av processkartläggningen upptäcktes onödiga aktiviteter. Dessa aktiviteter var tidskrävande och även möjligtvis kostnadsbärare och genom att eliminera dessa så kan man vinna mycket tid men även göra monetära besparingar bland processerna.Dessutom fanns det problem i processhanteringen då det inte fanns implementerade roller i processerna. Genom en belysning på behovet av Sex sigma och Kaizen så rekommenderades Göteborgs Kex att verkställa rollbeskrivningar för involverade personer i processerna. Göteborgs Kex kan på detta sätt säkerställa processernas stabilitet och effektivitet där grunden läggs på ständiga förbättringar i form av Sex Sigma och Kaizen. Eftersom Göteborgs Kex inte har någon Sex Sigma filosofi implementerad så finns det inga personer med roller eller ansvar för processhanteringen som kunde fatta beslut utan detta utsågs som ledningens uppgift. Genom att göra beräkningar på processen och belysa de onödiga aktiviteter som finns genom att säkra processerna med vetenskapligt beprövade metoder, så är processtyrning något som Göteborgs Kex kan tillämpa i hela företaget. / Program: Industriell ekonomi med inriktning logistik

The importance of quality improvement and excellent performance in the highly competitiveworld market, lead many organizations, their top managers, project managers, and engineers toimplement the new philosophies such as pull scheduling and lean principle at their organizations.This paper describes the Six Sigma principle and framework as a quality improvement strategythrough the successful business.Firstly, the background of the Six Sigma in industry will be described and statistical theorybehind it will be illustrated. Although the Six Sigma concept will be presented in terms ofprinciples, methodologies and framework, the main focus in this report is on adopting the SixSigma approach in construction projects which is still new concept in construction industry.Hence, adopting DMAIC procedure in the construction projects will be examined in this reportto give an overview of what is called Performance Improvement in Construction Projectbased on Six Sigma Principles.

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2004. / Includes bibliographical references (leaf 68). / In the early 1980's and 1990's, companies began to build upon the principles of Total Quality Management and developed there own unique quality systems. The most popular and well known of these systems is Six Sigma that was developed by Motorola and successfully adopted by others such as Allied Signal (now Honeywell) and most notably, General Electric. Six Sigma can be characterized as a highly formalized, process oriented improvement tool that is data focused. The Six Sigma process is normally performed by a diverse team, who attack a quality/process problem by analyzing process variation or in statistical terms, sigma. The foundations of Six Sigma are commitment from upper management, detailed training and a regimented diagnostic approach. Another quality operating system is the less known, but very successful, Achieving Competitive Excellence (ACE) operating system. This system was developed and is practiced by United Technologies Corporation (UTC). The ACE system is broader based than the Six-Sigma approach, however, ACE is not as data oriented as the Six Sigma approach. ACE revolves around the three principle categories of process improvement and waste elimination tools, decision-making tools, and problem solving tools. These tools impact issues as diverse, but not limited to, factory floor cleanliness, market feedback analysis, machine tool preventative maintenance and set up reduction. ACE is a combination of lean manufacturing and quality improvement philosophies. This paper provides an analysis of both the Six Sigma and ACE Quality Operating Systems. In the paper the systems are compared and contrasted. Further, strengths and weaknesses of each system are discussed. In particular, the analysis focuses on how ACE can leverage elements / (cont.) and aspects of Six Sigma. The analysis concludes that there are elements of Six Sigma that would benefit ACE. The paper identifies that the strength of Six Sigma's statistical approach and its positive impact on process certification could be beneficially applied to the ACE system. Further, there are recommendations for UTC to place more of an emphasis on ACE training and to accelerate its current efforts to better link quality and lean improvement to product engineering and design. / by Thomas C. Hutton. / M.B.A.

The thesis work is done at STENA Recycling Halmstad. The recycling facility has a yearly capacity to process 110.000 tonnes of material. There is an internal water system that circulates water to each of the separation processes and cleans before recirculation. Due to environmental concerns and government regulations the internal water cannot be let out of the facility. In addition, the internal water treatment system at STENA was not efficiently cleaning the internal water causing frequent plant maintenance issues.    The aim of the thesis is to improve the quality of the cleaned water from the internal water system. Qualitative data such as interviews and observations were combined with quantitative data that is measurements to reach the results, using a method called triangulation. Six Sigma (DMAIC) model was followed for the work execution.   The internal water treatment has five process steps. Five improvements are identified, implemented and evaluated. The thesis work goal of less than 2% dirt in the clean water is achieved by improving the overall performance of the cleaning system by 48.5% after implementing improvements. As a part of the last phase of six sigma approach which is control phase, an operation manual is developed to maintain the internal water treatment system.