Ο κύριος σκοπός της παρούσας εργασίας είναι να διερευνηθεί η χρήση ενός εναλλακτικού νέου γενετικού αλγορίθμου, που εφαρμόζεται στο ωράριο εργασίας και στον χρονοπρογραμματισμό των αστικών και υπεραστικών λεωφορείων στην Ελλάδα. Φαίνεται ότι η απόδοση επηρεάζεται από διάφορες παραμέτρους, όπως ισχυρούς ή ελαστικούς περιορισμούς, δεδομένου ενός συνόλου των οδηγών λεωφορείων, και ενός συνόλου δρομολογιών προς εκτέλεση. Πιο συγκεκριμένα, η μέθοδος που επιλέχθηκε για τη διεξαγωγή της παρούσας εργασίας είναι μια προσομοίωση των υπεραστικών λεωφορείων της πόλης της Πρέβεζας. Τέλος, τα αποτελέσματα της μελέτης δείχνουν ότι ο συνδυασμός των τεχνικών που παρουσιάστηκαν λειτουργεί αποτελεσματικά και να ξεπερνά όλα τα προηγούμενα μοντέλα σε μια απλή προσομοίωση. / The main target is to expand the usage of an alternative new generic algorithm, that is used in the timetable scheduling of urban and intercity buses in Greece. The performance is influenced by several factors. The method used is a simulation of the intercity buses of the city of Preveza. Finally, the results of the study shows that the combination of the techniques implemented works efficiently and overcomes the previous methods in a simple simulation.

nÃo hà / The continuous growth of populations and their concentration in great urban centers is reflected in an increasing demand for products and services in such areas. However, the distribution of a range of different products within the same geographic area, in many cases relying on the same transportation infrastructure, is becoming ever more complex and costly. The purpose of this study was to develop and test an application based on metaheuristic Genetic Algorithms (GA) designed to optimize the logistics of product distribution and delivery. In the literature this is known as the Travelling Salesman Problem (TSP) of the NPhard class. The method was initially tested on small and intermediate problems from the TSP library. Performance was satisfactory within an acceptable computational time. Subsequently, the method was tested in a real-life scenario: a specialized product distributor in Fortaleza (Northeastern Brazil). Again, results were satisfactory as the method was able to optimize the logistics of all the distributorâs delivery routes. / O contÃnuo crescimento das populaÃÃes e a concentraÃÃo nos centros urbanos fazem com que a demanda por produtos e serviÃos tambÃm cresÃa nestas regiÃes. Entretanto, dentro de um mesmo espaÃo geogrÃfico, e em muitos casos, com a mesma infraestrutura de transporte disponÃvel, a distribuiÃÃo fÃsica de produtos torna-se uma atividade cada vez mais complexa e onerosa. O objetivo deste trabalho foi propor uma aplicaÃÃo baseada na MetaheurÃstica Algoritimos GenÃticos (AG), para ser utilizada em serviÃos de distribuiÃÃo fÃsica de produtos a fim de obter maior eficiÃncia logÃstica na construÃÃo da sequÃncia de entregas. Na literatura este problema à conhecido como uma variante do Problema do Caixeiro Viajante (PCV), e pertence à classe NP-Hard. O mÃtodo foi testado em problemas de pequeno e mÃdio porte da TSP-LIBRARY. Os resultados foram obtidos com desempenho satisfatÃrio num tempo computacional aceitÃvel. Para aplicaÃÃo prÃtica, foi considerada uma empresa especialista em distribuiÃÃo de produtos com atuaÃÃo no municÃpio de Fortaleza. Os resultados dos testes prÃticos foram aceitÃveis, uma vez que o mÃtodo conseguiu otimizar todas as rotas observadas e praticadas pela empresa.

Since the advent of the computer in the late 1950s, scientists and engineers have pushed the limits of the computing power available to them to solve physical problems via computational simulations. Early computer languages evaluated program logic in a sequential manner, thereby forcing the designer to think of the problem solution in terms of a sequential process. Object-oriented analysis and design have introduced new concepts for solving systems of engineering problems. The term object-oriented was first introduced by Alan Kay [1] in the late 1960s; however, mainstream incorporation of object-oriented programming did not occur until the mid- to late 1990s. The principles and methods underlying object-oriented programming center around objects that communicate with one another and work together to model the physical system. Program functions and data are grouped together to represent the objects. This dissertation extends object-oriented modeling concepts to model algorithms in a generic manner for solving interconnected, multi-domain problems. This work is based on an extension of Graph Trace Analysis (GTA) which was originally developed in the 1990's for power distribution system design. Because of GTA's ability to combine and restructure analysis methodologies from a variety of problem domains, it is now being used for integrated power distribution and transmission system design, operations and control. Over the last few years research has begun to formalize GTA into a multidiscipline approach that uses generic algorithms and a common model-based analysis framework. This dissertation provides an overview of the concepts used in GTA, and then discusses the main problems and potential generic algorithm based solutions associated with design and control of interdependent reconfigurable systems. These include: • Decoupling analysis into distinct component and system level equations. • Using iterator based topology management and algorithms instead of matrices. • Using composition to implement polymorphism and simplify data management. • Using dependency components to structure analysis across different systems types. • Defining component level equations for power, gas and fluid systems in terms of across and though variables. This dissertation presents a methodology for solving interdependent, multi-domain networks with generic algorithms. The methodology enables modeling of very large systems and the solution of the systems can be accomplished without the need for matrix solvers. The solution technique incorporates a binary search algorithm for accelerating the solution of looped systems. Introduction of generic algorithms enables the system solver to be written such that it is independent of the system type. Example fluid and electrical systems are solved to illustrate the generic nature of the approach. / Ph. D.

Model checking is a powerful technique for analyzing reach ability and temporal properties of finite state systems. Model-checking finite state systems has been well-studied and there are well known efficient algorithms for this problem. However these algorithms may not terminate when applied directly to in finite state systems. Counter systems are a class of in fininite state systems where the domain of counter values is possibly in finite. Many practical systems like cache coherence protocols, broadcast protocols etc, can naturally be modeled as counter systems. In this thesis we identify a class of counter systems, and propose a new technique to check whether a system from this class satires’ a given CTL formula. The key novelty of our approach is a way to use existing reach ability analysis techniques to answer both \until" and \global" properties; also our technique for \global" properties is different from previous techniques that work on other classes of counter systems, as well as other classes of in finite state systems. We also provide some results by applying our approach to several natural examples, which illustrates the scope of our approach.