Identification of nonlinear dynamical models of a black box nature involves both structure decisions (i.e., which regressors to use and the selection of a regressor function), and the estimation of the parameters involved. The typical approach in system identification is often a mix of all these steps, which for example means that the selection of regressors is based on the fits that is achieved for different choices. Alternatively one could then interpret the regressor selection as based on hypothesis tests (F-tests) at a certain confidence level that depends on the data. It would in many cases be desirable to decide which regressors to use, independently of the other steps. A survey of regressor selection methods used for linear regression and nonlinear identification problems is given. In this thesis we investigate what the well known method of analysis of variance (ANOVA) can offer for this problem. System identification applications violate many of the ideal conditions for which ANOVA was designed and we study how the method performs under such non-ideal conditions. It turns out that ANOVA gives better and more homogeneous results compared to several other regressor selection methods. Some practical aspects are discussed, especially how to categorise the data set for the use of ANOVA, and whether to balance the data set used for structure identification or not. An ANOVA-based method, Test of Interactions using Layout for Intermixed ANOVA (TILIA), for regressor selection in typical system identification problems with many candidate regressors is developed and tested with good performance on a variety of simulated and measured data sets. Typical system identification applications of ANOVA, such as guiding the choice of linear terms in the regression vector and the choice of regime variables in local linear models, are investigated. It is also shown that the ANOVA problem can be recast as an optimisation problem. Two modified, convex versions of the ANOVA optimisation problem are then proposed, and it turns out that they are closely related to the nn-garrote and wavelet shrinkage methods, respectively. In the case of balanced data, it is also shown that the methods have a nice orthogonality property in the sense that different groups of parameters can be computed independently.

An important and challenging problem that Process Engineers frequently encounter is the determination of appropriate control structures that minimize the loss of process performance under the effect of uncertainties. This can be achieved by selecting subsets of controlled and manipulated variables and designing their interconnection (controller synthesis). This is known as the Control Structure Selection Problem (CSSP) In this Thesis, a systematic optimization methodology, based on the back-off concept proposed by Prof J. D. Perkins and co-workers, is presented for the CSSP. The proposed formulation offers the following improvements: a) improves the accuracy of calculations and b) reduces computational time and effort. Specifically, the error involved in the approximation of the nonlinear constraint that defines the magnitude of the back-off vector (needed for control structure selection) is reduced by the introduction of a more accurate linear approximation. In addition, the methodology is able to track the effect of simultaneously occurring disturbances at the same time and estimate their worst impact on process economics. The reduction of computational time is achieved by eliminating the state variables from the final formulation. In this way, the number of equations needed for the CSSP solution is significantly reduced and allows the algorithm to locate the solution faster without affecting the performance. The proposed methodology is firstly applied in a classical distillation column (medium scale) and in a complex and highly nonlinear reactive distillation column (large scale). The results obtained from these case studies made the way for the application of the methodology on the plantwide problem of the benchmark Vinyl Acetate monomer production plant in order to demonstrate the benefits of the proposed algorithm. / Η παρούσα εργασία παρουσιάζει μια συστηματική μεθοδολογία για την εύρεση βέλτιστων δομών ρύθμισης σε συστήματα μεγάλης κλίμακας, όπως για παράδειγμα ολοκληρωμένες μονάδες παραγωγής και βασίζεται στην ελαχιστοποίηση των επιπτώσεων των διαταραχών στην οικονομική απόδοση μιας διεργασίας. Το κύριο στοιχείο της μεθοδολογίας είναι το διάνυσμα υποχώρησης από τους ενεργούς περιορισμούς (μ), το οποίο προτάθηκε από τον Prof. J.D. Perkins και την ερευνητική του ομάδα. Η προτεινόμενη μεθοδολογία ενσωματώνει τα κύρια χαρακτηριστικά της μεθοδολογίας του διανύσματος (μ) και παρουσιάζει μια σειρά βελτιώσεων με στόχο τον περιορισμό των μειονεκτημάτων που απέτρεπαν την εφαρμογή της σε συστήματα μεγάλης κλίμακας. Οι βελτιώσεις επικεντρώνονται σε δύο ζητήματα: α) αύξηση της ακρίβειας των υπολογισμών και β) μείωση του υπολογιστικού φόρτου και χρόνου. Η αύξηση της ακρίβειας των υπολογισμών εντοπίζεται στην κατασκευή ενός βελτιωμένου προσεγγιστικού προβλήματος για την κατασκευή κάτω φραγμάτων για τη βέλτιστη λύση. Η βασική ιδέα πίσω από τη προτεινόμενη βελτίωση βασίζεται στη προσέγγιση των μη γραμμικών όρων που εμφανίζονται με ένα σύνολο γραμμικών εξισώσεων. Επίσης για πιο ακριβείς υπολογισμούς, εξετάζεται κάθε διαταραχή ξεχωριστά σε ένα εύρος συχνοτήτων και στη συνέχεια η μέγιστη επίδραση της καθεμίας χρησιμοποιείται από τον αλγόριθμο έτσι ώστε να υπολογιστεί η μέγιστη δυνατή επίπτωση τους στην οικονομική απόδοση της διεργασίας Η μείωση του υπολογιστικού φόρτου και χρόνου επιτυγχάνεται μέσω της απαλοιφής των μεταβλητών κατάστασης. Με αυτό τον τρόπο, ο αριθμός των εξισώσεων που απαιτείται για την επίλυση του προβλήματος μειώνεται σημαντικά και εντοπίζει τη βέλτιστη λύση σε μικρότερο αριθμό επαναλήψεων της μεθόδου, γεγονός που επιτρέπει την εφαρμογή της σε προβλήματα μεγάλης κλίμακας. Τέλος, η προτεινόμενη μεθοδολογία έχει εφαρμοστεί σε δύο αποστακτικές στήλες και τα αποτελέσματα άνοιξαν το δρόμο για την εφαρμογή της μεθόδου σε μια μονάδα παραγωγής οξικού μεθυλεστέρα, όπου τα πλεονεκτήματα της μεθόδου είναι περισσότερο ορατά και πρακτικά χρήσιμα.

Στα πλαίσια της εργασίας αυτής μελετήθηκε η συμβολή της γλώσσας προγραμματισμού scratch στη διδασκαλία του προγραμματισμού και τη δημιουργία υπολογιστικών εφαρμογών, στο μάθημα Τεχνολογίες Πληροφορίας και επικοινωνιών στην Πρωτοβάθμια Εκπαίδευση στις τελευταίες τάξεις του δημοτικού σχολείου. Στην παρούσα έρευνα περιγράφεται ο σχεδιασμός και η υλοποίηση του εκπαιδευτικού σεναρίου, καθώς και τα αποτελέσματά του ως προς την διαφοροποίηση της γνωστικής συμπεριφοράς των μαθητών ως προς την οικοδόμηση της δομής επιλογής, απλής και σύνθετης. Οι μαθητές υλοποίησαν 11 δραστηριότητες με τα αντίστοιχα φύλλα εργασίας τους, στο εργαστήριο πληροφορικής του σχολείου. Εξετάστηκαν οι δυσκολίες που συνάντησαν οι μαθητές στην υλοποίηση των δραστηριοτήτων, καθώς και τα προβλήματα που αντιμετώπισαν. Μελετήθηκε η συμβολή του εκπαιδευτικού σεναρίου το οποίο αναπτύχθηκε για την διδασκαλία της δομής επιλογής απλής και σύνθετης, καθώς και η συμβολή της αποτελεσματικής συνεργασίας των μαθητών ως μέλη ομάδων εργασίας. Τα αποτελέσματα έδειξαν ότι οι μαθητές είχαν ελάχιστα προβλήματα στην υλοποίηση των συνθηκών, ενώ περισσότερα από αυτά τα προβλήματα προέκυπταν όταν έπρεπε να εισάγουν λογικούς τελεστές. Εντοπίστηκε δυσκολία στην απλή δομή επιλογής με την εισαγωγή εντολών στην «αλλιώς». Διαπιστώθηκε ότι η χρήση του περιβάλλοντος scratch είναι ιδιαίτερα ελκυστική για τους μαθητές και ευνοεί την οικοδόμηση της δομής επιλογής σε συνδυασμό με κατάλληλα διαμορφωμένο εκπαιδευτικό σενάριο. Στην τελευταία δίωρη δραστηριότητα έγινε χρήση του ρομποτικού πακέτου Lego wedo με σκοπό την καλύτερη κατανόηση της χρήσης της δομής επιλογής. Ένα άλλο εύρημα της παρούσας ερευνητικής εργασίας αποτελεί η διαπίστωση ότι ένα κατάλληλα διαμορφωμένο κλίμα συνεργασίας ευνοεί και βελτιώνει την απόδοση των μαθητών. Με βάση τα παραπάνω, μπορούν να διατυπωθούν προτάσεις για την βελτίωση του συγκεκριμένου μαθήματος στο δημοτικό σχολείο και την ανάπτυξη κατάλληλου εκπαιδευτικού υλικού. / In this work, we studied the contribution of the programming language scratch in teaching programming and creating computer applications course in Information and Communications Technology in Primary Education in the last grades of elementary school. This research describes the design and implementation of the educational scenario and its effects on the differentiation of cognitive behavior of pupils in the building structure selection, simple and complex. Students implemented 11 activities with corresponding worksheets in the school computer lab . Examined the difficulties encountered by students in the implementation of activities, and the problems encountered. We studied the contribution of the educational scenario was developed for the teaching of structure selection simple and complex , and the contribution of the effective cooperation of students as members of working groups . The results showed that students had few problems in the implementation of treaties, while most of these problems arose when they had to introduce logical operators. Detected difficulty simple structure selection by enter commands into the " else ".It was found that the use of ambient scratch is especially attractive to students and conducive to building structure selection in conjunction with appropriately designed educational scenario . In the last two-hour activity we used the robotic Lego wedo package in order to better understand the use of structure selection. Another finding of this study is that a properly configured and working atmosphere conducive improves student performance. According this research, we can make suggestions for the improvement of the course in elementary school and the development of appropriate educational material.

Turing Award winner Niklaus Wirth famously noted, `Algorithms + Data Structures = Programs', and it follows that data structures should be carefully considered for effective application development. In fact, data structures are the main focus of program understanding, performance engineering, bug detection, and security enhancement, etc. Our research is aimed at providing effective techniques for analyzing and improving data structure usage in fundamentally new approaches: First, detecting data structures; identifying what data structures are used within an application is a critical step toward application understanding and performance engineering. Second, selecting efficient data structures; analyzing data structures' behavior can recognize improper use of data structures and suggest alternative data structures better suited for the current situation where the application runs. Third, detecting memory leaks for data structures; tracking data accesses with little overhead and their careful analysis can enable practical and accurate memory leak detection. Finally, offloading time-consuming data structure operations; By leveraging a dedicated helper thread that executes the operations on the behalf of the application thread, we can improve the overall performance of the application.

The problem of designing control systems for entire plants is studied. A review of previous works, available techniques and current research challenges is presented, followed by the description of some theoretical tools to improve plantwide control, including the proposal of an augmented lexicographic multi-objective optimization procedure. With these, an augmented hierarchical plantwide control design technique and an optimal multi-objective technique for integrated control structure selection and controller tuning are proposed. The main contributions of these proposed techniques are the inclusion of system identification and optimal control tuning as part of the plantwide design procedure for improved results, support to multi-objective control specifications and support to any type of plant and controllers. Finally, the proposed techniques are applied to industrial benchmarks to demonstrate and validate its applicability. / O problema de projetar sistemas de controle para plantas inteiras é estudado. Uma revisão de trabalhos anteriores, técnicas disponíveis e atuais desafios de pesquisa é apresentada, seguida da descrição de algumas ferramentas teóricas para melhorar o controle plantwide, incluindo a proposta de um procedimento de otimização multi-objetivo lexicográfico aumentado. Com tais elementos, são propostas uma nova técnica hierárquica aumentada de projeto de sistemas de controle plantwide e uma técnica multi-objetivo para seleção de estrutura de controlador integrada à sintonia ótima do controlador. As principais contribuições das técnicas propostas são a inclusão de identificação de sistemas e sintonia ótima de controladores como parte do procedimento de projeto de controle plantwide para melhores resultados, suporte a especificações multi-objetivo e suporte a quaisquer tipos de plantas e controladores. Finalmente, as técnicas propostas são aplicadas a benchmarks industriais para demonstrar e validar sua aplicabilidade.

The problem of designing control systems for entire plants is studied. A review of previous works, available techniques and current research challenges is presented, followed by the description of some theoretical tools to improve plantwide control, including the proposal of an augmented lexicographic multi-objective optimization procedure. With these, an augmented hierarchical plantwide control design technique and an optimal multi-objective technique for integrated control structure selection and controller tuning are proposed. The main contributions of these proposed techniques are the inclusion of system identification and optimal control tuning as part of the plantwide design procedure for improved results, support to multi-objective control specifications and support to any type of plant and controllers. Finally, the proposed techniques are applied to industrial benchmarks to demonstrate and validate its applicability. / O problema de projetar sistemas de controle para plantas inteiras é estudado. Uma revisão de trabalhos anteriores, técnicas disponíveis e atuais desafios de pesquisa é apresentada, seguida da descrição de algumas ferramentas teóricas para melhorar o controle plantwide, incluindo a proposta de um procedimento de otimização multi-objetivo lexicográfico aumentado. Com tais elementos, são propostas uma nova técnica hierárquica aumentada de projeto de sistemas de controle plantwide e uma técnica multi-objetivo para seleção de estrutura de controlador integrada à sintonia ótima do controlador. As principais contribuições das técnicas propostas são a inclusão de identificação de sistemas e sintonia ótima de controladores como parte do procedimento de projeto de controle plantwide para melhores resultados, suporte a especificações multi-objetivo e suporte a quaisquer tipos de plantas e controladores. Finalmente, as técnicas propostas são aplicadas a benchmarks industriais para demonstrar e validar sua aplicabilidade.

En este trabajo de Tesis se evalúo de manera extensiva la diversidad genética presente en los maíces nativos de Latinoamérica, combinando datos fenotípicos y genotípicos, con dos propósitos diferentes. El primero, un estudio donde la diversidad genética, las relaciones interpoblacionales y la estructura poblacional de los materiales nativos permitieron ligar aspectos históricos, antropológicos y arqueológicos del maíz para crear una historia consolidada de la migración del maíz desde su centro de origen en Mesoamérica hacia el Caribe y Sudamérica. El segundo, es explorado el potencial de las razas de maíz para proporcionar nuevos alelos favorables para mejoramiento. La evaluación fenotípica y genotípica conjunta de accesiones del Banco de Germoplasma con material mejorado por CIMMYT permitió identificar fuentes de variación alélica importante para algunos caracteres de interés como tolerancia a la sequía. La caracterización de la diversidad genética de los materiales nativos para la conservación y explotación con fines de mejoramiento es un enfoque muy prometedor en particular con el desarrollo constante de nuevas herramientas genéticas. / In this thesis work, the genetic diversity of Latin American maize landraces was evaluated extensively combining phenotypic and genotypic data, for two different purposes. First, to study the genetic diversity, relationships, and population structure of native materials allowing the linkage of historical, anthropological and archaeological data to create a consolidated history of maize migration from its origin center in Mesoamerica towards The Caribbean and South America. Second, to explore the potential of maize landraces to provide new elite alleles for breeding, the phenotypic and genotypic characterization of gene bank accessions compared to improved material from CIMMYT allowed the identification of important sources of allelic variation for traits of interest including drought tolerance. The characterization of native genetic diversity for conservation and exploitation towards breeding is a very promising approach, especially considering on going development of new genetic tools and methodologies

Diploma thesis explores the diversity of demographic behavior depending on marital status and is aimed at summarizing the effect of marital status on demographic behavior as a whole. The first phase deals with the concepts of impact of marital status on demographic behavior, explains the theory of selection and causality and outlines the historical development of nuptiality and divorce by using basic indicators. The practical part is based on the results of Population and Housing Censuses during the period 1961-2011 and compares the changes in the structure of the Czech population by sex, age and marital status between censuses. Emphasis is placed on the period after 1990. Furthermore, in separate chapters is mapped out how marital status affects demographic processes of fertility, abortion, nuptiality and mortality. In the case of fertility exploration is emphasized increasing extramarital fertility, as more and more children are born outside marriage, especially to single mothers. By using age-specific and standardized rates are analyzed changes in the development of individual demographic processes between censuses for all categories of marital status. Standardization of mortality for the years 1961, 1970 and 1980 is made on the basis of the formation of shortened life tables and the subsequent modeling of mortality at higher ages. In connection of changing structure of the population by marital status, as the proportion of unmarried and divorced people is growing and the share of people living in a marriage is decreasing, is judged attitude of the Czech public toward marriage and family according to surveys results available.

En este trabajo de Tesis se evalúo de manera extensiva la diversidad genética presente en los maíces nativos de Latinoamérica, combinando datos fenotípicos y genotípicos, con dos propósitos diferentes. El primero, un estudio donde la diversidad genética, las relaciones interpoblacionales y la estructura poblacional de los materiales nativos permitieron ligar aspectos históricos, antropológicos y arqueológicos del maíz para crear una historia consolidada de la migración del maíz desde su centro de origen en Mesoamérica hacia el Caribe y Sudamérica. El segundo, es explorado el potencial de las razas de maíz para proporcionar nuevos alelos favorables para mejoramiento. La evaluación fenotípica y genotípica conjunta de accesiones del Banco de Germoplasma con material mejorado por CIMMYT permitió identificar fuentes de variación alélica importante para algunos caracteres de interés como tolerancia a la sequía. La caracterización de la diversidad genética de los materiales nativos para la conservación y explotación con fines de mejoramiento es un enfoque muy prometedor en particular con el desarrollo constante de nuevas herramientas genéticas. / In this thesis work, the genetic diversity of Latin American maize landraces was evaluated extensively combining phenotypic and genotypic data, for two different purposes. First, to study the genetic diversity, relationships, and population structure of native materials allowing the linkage of historical, anthropological and archaeological data to create a consolidated history of maize migration from its origin center in Mesoamerica towards The Caribbean and South America. Second, to explore the potential of maize landraces to provide new elite alleles for breeding, the phenotypic and genotypic characterization of gene bank accessions compared to improved material from CIMMYT allowed the identification of important sources of allelic variation for traits of interest including drought tolerance. The characterization of native genetic diversity for conservation and exploitation towards breeding is a very promising approach, especially considering on going development of new genetic tools and methodologies