Made available in DSpace on 2014-06-12T16:01:17Z (GMT). No. of bitstreams: 2 arquivo7298_1.pdf: 1333279 bytes, checksum: 0672c997ae12d1dc44880cf3a5be3874 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2005 / A aplicação mais recorrente da Criptografia é a sua utilização quando duas partes desejam trocar informações secretas de forma privada, porém com o surgimento das grandes redes de computadores, outras formas e técnicas surgiram, entre elas o aparecimento da Computação Segura entre Múltiplos Participantes (MPC). A MPC consiste de duas ou mais partes, onde cada uma possui um conjunto de dados secretos e deseja computar uma determinada função f , que recebe como entrada as informações secretas de cada parte. Ao final do protocolo, cada participante obterá apenas o resultado da função f , não sendo reveladas as entradas secretas. Um exemplo real seria um paciente que possui o seu código genético seqüenciado e gostaria de fazer uma consulta em um banco de dados de DNAs relacionados a doenças de um hospital. Todavia, nem o doente quer que o hospital conheça seu DNA ou seu estado de saúde, nem o hospital quer mostrar todo o seu banco de DNAs para esse paciente. Esse e outros tipos de problema podem ser solucionados utilizando-se em especial a MPC. Apesar de existirem soluções genéricas para a modelagem de Protocolos Seguros entre Múltiplos Participantes, essas se mostram inviáveis na prática devido ao seu alto custo computacional. É nesse contexto que se situa o presente trabalho. Foram desenvolvidos vários protocolos eficientes entre dois participantes em duas subáreas específicas da Computação Científica Segura, particularmente na Álgebra Linear Privada e na Estatística Privada. Entre os problemas resolvidos podem-se destacar: o cálculo de determinantes, autovalores, autovetores, média, média geométrica, média harmônica, curtose, variância e muitos outros. No futuro, cada protocolo apresentado poderá servir de bloco para a implementação de novas aplicações, tais como mineração de dados segura, votação na internet, computação segura entre múltiplos bancos de dados, etc...

Doctor of Philosophy / Food Science Institute / Jayendra K. Amamcharla / Lactose is commercially produced from whey, whey permeate, or milk permeate as α-lactose monohydrate in crystalline form. Focused Beam Reflectance Measurement (FBRM) as a potential tool for in situ monitoring of lactose crystallization at concentrations relevant to the dairy industry was evaluated. Applicability of FBRM at supersaturated lactose concentrations 50%, 55%, and 60% (w/w) was reported in comparison with Brix values obtained from a Refractometer during isothermal crystallization at temperatures 20ºC and 30ºC. FBRM technique was shown to be a valuable tool for monitoring chord length distributions during lactose crystallization. In a different study, the influence of cooling rate during crystallization of lactose in concentrated permeates was studied. Three cooling rates accounting for approximately 17, 11, and 9 h were applied during lactose crystallization to evaluate the lactose crystal yield and quality of lactose crystals. There was no significant difference (P>0.05) found in lactose crystal yield, mean particle size obtained at the end of crystallization. This study suggested that increasing the cooling rate during lactose crystallization within the range explained in this study can save approximately 8 h of crystallization time. These studies evaluated FBRM as a potential tool to monitor lactose crystal chord lengths and counts. Also, process improvements were suggested to increase the productivity of lactose crystallization process by reducing the crystallization time. In chapters 5 and 6, calcium-reduced milk protein concentrates (MPCs) were used as an ingredient to improve the stability of high-protein dairy beverages. Heat stability increased significantly (P>0.05) in 8% protein solutions made from 20% calcium-reduced MPC. A significant increase in heat stability was observed in beverages formulated with 20% calcium-reduced MPC in the absence of chelating agent. In another study, it was evident that the dairy beverage formulation with 20% calcium-reduced MPC showed no sedimentation and age gelation indicating an improved storage stability. These studies confirmed that 20% calcium reduced MPC contributed towards improved heat stability and storage stability of the high-protein beverages.

Approximately 10 000 individuals in Sweden are diagnosed with aphasia every year, which can result in severe communication difficulties. Conversation partner training (CPT) is a treatment that aims to help the person with aphasia and their communication partner to have a functional communication. CPT has shown to be an efficient treatment and is recommended in the Swedish national stroke rehabilitation guidelines. The present study examines the inter- and intra-rater reliability of five different CPT assessment materials with intraclass correlation (ICC) for CPT in aphasia. The assessment materials evaluated and compared in this study were Measure of skill in supported conversation (MSC), Measure of participation in conversation (MPC) and the Swedish adaptations Measure of interaction in conversation (MIC/MIK), Stöd i konversation (SiK) and Deltagande i konversation (DiK). The study also examines if assessment training increases the inter-rater reliability, and also if there is any correlation between the type and severity of aphasia and inter-rater reliability. Fourteen dyads participated in the study. The analyses are based on 10 minutes long video clips where the dyads are having a conversation on an optional topic. The results indicated that the assessment materials with the highest inter-rater reliability were SiK and DiK (ICC > 0.65, p < 0,001) and the assessment material with highest intra-rater reliability was MSC for assessor number one (0.91, p < 0.001) and MIC for assessor number two (0.83, p < 0.001). The results also imply that there are no significant differences in inter-rater reliability between assessments before and after assessment training. Correlation between type of aphasia and inter-rater reliability was found in SiK (r = 0.65 p = 0.013). No correlation was found for the variable severity of aphasia and inter-rater reliability. Varje år drabbas ca 10 000 personer av afasi i Sverige, vilket kan medföra stora kommunikativa svårigheter. Kommunikationspartnerträning (KPT) är en behandling som hjälper den drabbade och dennes samtalspartner att kommunicera på ett funktionellt sätt. Studier visar att KPT är en effektiv behandlingsmetod och i Socialstyrelsens reviderade nationella strokeriktlinjer rekommenderas denna metod. Föreliggande studie undersöker inter- och intrabedömarreliabiliteten med intraclass correlation (ICC) för fem olika bedömningsmaterial för KPT vid afasi. Bedömningsmaterialen som jämförts och utvärderats är Measure of skill in supported conversation (MSC), Measure of participation in conversation (MPC), och de svenska anpassningarna Mått på interaktion i kommunikation (MiK) och Stöd i konversation (SiK) respektive Deltagande i konversation (DiK). Studien utforskar också om samstämmighetsträning förbättrar interbedömarreliabiliteten samt om det finns något samband mellan typ och grad av afasi och interbedömarreliabilitet. Fjorton dyader deltog i studien. Analysen genomfördes utifrån filmklipp på cirka 10 minuter där deltagarna samtalade om valfritt ämne. Resultaten visade att SiK och DiK hade högst interbedömarreliabilitet (ICC > 0,65, p < 0,001). Bedömningsmaterialet med högst intrabedömarreliabilitet var MSC för bedömare 1 (0,91, p < 0,001), och MIK för bedömare 2 (0,83 p < 0,001). Resultaten i föreliggande studie visade inga signifikanta skillnader i interbedömarreliabilitet mellan testning före respektive efter träning av samstämmighet. Korrelation mellan typ av afasi och interbedömarreliabilitet kunde påvisas för SiK (r = 0,65 p = 0,013). Korrelation mellan grad av afasi och interbedömarreliabilitet kunde ej påvisas.

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The need to save energy, cut costs, and increase profit margin in process manufactureincreases continually. There is also a global drive to reduce energy use and cut down co2 emission and combat climate change. These in turn have led to more stringent requirements on process control performance. Hence, the requirements for modern systems are often not achievable using classical control techniques. Therefore, advanced control strategies are often required to ensure optimal process performance. Despite these challenges, PID has continued to be the dominant industrial control scheme. However, for systems with complex dynamics and/or high performance requirements, PID control may not be sufficient. Therefore, a significant number of industrial control loops are not performing optimally and more advanced control than PID may be required in order to achieve optimal performance. MPC is one of the advanced control schemes that has had a significant impact in the industry. Despite the benefits associated with the implementation of MPC, the technology has remained a niche application in process manufacture. This thesis seeks to address these issues by developing ways that could lead to widespread application of MPC. In the first part of this thesis, a study was carried out to understand the characteristics of processes that would benefit from the application of MPC at the regulatory control level even in the single-input single-output (SISO) case. This is a departure from the common practice in which MPC is applied at the supervisory control layer delivering set points to PID controllers at the regulatory control layer. Both numerical simulation and industrial studies were used to show and quantify benefits of MPC for SISO applications at the regulatory control layer. Some issues that have led to the limited application of MPC include the cost and human efforts associated with modelling and controller design. And to achieve high process performance, accurate models are required. To address this issue, in the second part of this thesis, a novel technique for designing MPC from routine plant data – routine data MPC (RMPC) is proposed. The proposed technique was successfully implemented on process models. This technique would reduce the high human cost associated with MPC deployment, which could make it a widespread rather than niche application in the process manufacturing industry.

Control predictivo basado en modelos (MPC) es una metodología de control ampliamente utilizada en la industria por su habilidad para controlar procesos multivariable con restricciones en sus entradas y sus salidas. Se distinguen dos fases en la implementación de MPC: identificación y control. El propósito de esta tesis es doble: realizar contribuciones en la identificación para MPC y proponer una nueva metodología de control MPC. La respuesta en bucle cerrado de una implementación de MPC depende, en gran medida, de la capacidad de predicción del modelo; luego la identificación del modelo es un punto crucial en MPC y la parte que a menudo exige la mayor parte del tiempo del proyecto. El primer objetivo que cubre la tesis es la identificación para MPC. Puesto que un modelo es una aproximación del comportamiento de un proceso, dicha aproximación se puede hacer teniendo en cuenta el fin que se le va a dar al modelo. En MPC, el modelo se utiliza para realizar predicciones dentro de una ventana futura, luego la identificación para MPC (MRI) tiene en cuenta dicho uso del modelo y considera los errores de predicción dentro de dicha ventana para el ajuste de los parámetros del modelo. En esta tesis, se cubren tres temas dentro de MRI. Primero se define MRI y las distintas formas de abordarlo. Luego se compara en términos de MRI el ajuste de un modelo con múltiples entradas y múltiples salidas con el ajuste de varios modelos con múltiples entradas y una salida concluyendo que el ajuste de un único modelo con múltiples entradas y múltiples salidas proporciona mejores resultados en términos de MRI para horizontes de predicción lo suficientemente grandes. Por último, se propone el algoritmo PLS-PH para implementar MRI con modelos paramétricos en el caso de correlación en los datos de identificación. PLS-PH es un método de optimización numérica por búsqueda lineal basado en PLS (mínimos cuadrados parciales). Se muestra en un ejemplo como PLS-PH es capaz de proporcionar mejores modelos que las técnicas convencionales de MRI en modelos paramétricos en el caso de correlación en los datos de identi ficación. Una vez obtenido el modelo se puede formular el controlador predictivo. En esta tesis se propone LV-MPC, un controlador predictivo para procesos continuos que implementa la optimización en el espacio de las componentes principales. / Laurí Pla, D. (2012). MPC: Relevant Identification and Control in the Latent Variable Space [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15178 / Palancia

Increased safety and productivity are driving factors for the trend in the mining industry where equipment and machines increasingly get automated. An example is the load-haul-dump vehicle, which is a machine that is used for transport of ore in underground mines. The cyclic load-haul-dump process is well suited for automation and automated loaders are commercially available today. Recent advances in autonomous driving have raised questions if there are efficiency gains that can be made by improving the path following algorithms that are used in the control. The aim of this thesis is to investigate the usage of model predictive control for path following for center-articulated mining vehicles. Two path following nonlinear model predictive controllers are designed and implemented. One controller is based on an error dynamics model, formulated as a regulation problem and implemented with the open source NMPC-library GRAMPC. The second controller is based on a kinematic model, formulated as a reference tracking NMPC problem and implemented using the embedded-MPC software tool FORCESPRO. The controllers are simulated on the same hardware that is used in real load-haul-dump vehicles, in a simulation environment provided by Epiroc Rock Drills AB. The results from the simulations show that both controllers can successfully follow a path, with a similar level of path error and less aggressive control actions compared to the current path following controller. The implemented controllers perform the control computations within a range of milliseconds on the embedded hardware, which is fast enough for real-time operation of the load-haul-dump vehicle.

The process to induct air into engine cylinders, via the air inlet system and cylin-der port valves, is referred to as the "gas-exchange". Control is achieved by theturbo-charger, the intake throttle plate and the variable valve timing (VVT) sys-tem. These actuation systems traditionally use separate control with indepen-dent SISO feedback. There are however physical couplings that affect the con-trol performance. This thesis work looks at MPC control methods for a robustcontrol strategy. MPC methods are typically used for systems with slow dynam-ics, due to computational limits. But new advances in CPU performance shouldallow for real-time implementations for engine control. / <p>Redan framlagt exjobbet</p>

This thesis deals with the design of a lecture model of an inverse pendulum controled by a flywheel, which is a system of an unstable beam with an electromotor and a reaction wheel at its end. The moment of motor acting on the flywheel also causes a moment acting on the beam, which is the way the system is controled. The device works connected to a personal computer.

In this thesis an equation of heat conduction including phase and structural changes is derived, involving various boundary conditions. It seems to be the most suitable to calculate the equation by enthalpy method. In this equation not only enthalpy occurs, but also the temperature, and in consequence the relationship between these variables is quite complicated. In this paper I use the values measured or calculated using solidifcation models. The calculation is implemented in Matlab Simulink, which is a very popular blocks scheme in common practice of regulation. The calculation is based on steady state set up with help of experts and as a result, the program could be put into practice. The program calculates the intensity of cooling according to the initial casting speed, casting inlet temperature and the desired temperature curves. The rate of inuence of cooling can be changed according to the given criteria. The thesis compares the surface temperatures and cooling in the case of a predictive controller is or is not applied in the program.