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<p>Modern state-of-the-art equation based object oriented modeling languages such as Modelica have enabled easy modeling of large and complex physical systems. When such complex models are to be simulated, simulation tools typically perform a number of optimizations on the underlying set of equations in the modeled system, with the goal of gaining better simulation performance by decreasing the equation system size and complexity. The tools then typically generate efficient code to obtain fast execution of the simulations. However, with increasing complexity of modeled systems the number of equations and variables are increasing. Therefore, to be able to simulate these large complex systems in an efficient way parallel computing can be exploited.</p><p>This thesis presents the work of building an automatic parallelization tool that produces an efficient parallel version of the simulation code by building a data dependency graph (task graph) from the simulation code and applying efficient scheduling and clustering algorithms on the task graph. Various scheduling and clustering algorithms, adapted for the requirements from this type of simulation code, have been implemented and evaluated. The scheduling and clustering algorithms presented and evaluated can also be used for functional dataflow languages in general, since the algorithms work on a task graph with dataflow edges between nodes.</p><p>Results are given in form of speedup measurements and task graph statistics produced by the tool. The conclusion drawn is that some of the algorithms investigated and adapted in this work give reasonable measured speedup results for some specific Modelica models, e.g. a model of a thermofluid pipe gave a speedup of about 2.5 on 8 processors in a PC-cluster. However, future work lies in finding a good algorithm that works well in general.</p> / Report code: LiU-Tek-Lic-2002:06.

In this study, an approach is proposed to model and simulate the systems engineering process of design projects. One of the main aims is to model the systems engineering process, treating the process itself as a complex system. A conceptual model is developed as a result of a two-phase survey conducted with systems engineers. The conceptual model includes two levels of activity networks. Each first level systems engineering activity has its own network of second level activities. The model is then implemented in object oriented modeling language, namely SysML, using block definition diagrams and activity diagrams. Another aim is to generate a discrete event simulation model of the process for performance evaluation. For this purpose the SysML model is transformed to an Arena model using an Excel interface and VBA codes. Three deterministic and three stochastic cases are created to represent systems engineering process alternatives, which originate from the same conceptual model but possess different activity durations, resource availabilities and resource requirements. The scale of the project and the effect of uncertainty in activity durations are also considered. The proposed approach is applied to each of these six cases, developing the SysML models, transforming them to Arena models, and running the simulations. Project duration and resource utilization results are reported for these cases.

The cadastre contains parcel related data which must be up-to-date. The cadastral data in any country constitute a very big dataset. Therefore parcel related data should be carefully managed. Today, using a database is an effective way of data management. The relational database management system can be a good one for parcel related data. However when the information system concept is considered, just relational database management system is not enough. Some tools are needed in order to manipulate the data in the relational database management system. Object oriented analysis and design is a good choice to develop these tools. In this study, a parcel-based information system is developed and it is implemented for &Ccedil / ankaya Municipality. During the development relational database management system is used for attribute data management, and object-oriented analysis and design is used for development of application to manipulate the data in the relational database management system. The cadastral data are separated into two parts and each part is handled separately. The first part is the geographic or spatial data. These data are handled by the help of the MapInfo Professional Version 6.5. The other part is the attributes of these spatial data. For this part, relational database is designed and implemented on Microsoft SQL Server Version 2000. During the development of the relational database, conceptual database design is performed by enhanced entity-relationship (EER) model. Then in the logical design, the conceptual model is mapped into the relational model. After data storage area is created, the application is developed on that data by using principles of object-oriented design and analysis and unified modeling language. By the help of the software developed, the data management can be carried out easily. By this study, a solution is proposed for the cadastral data management problem of the municipalities, and this study is one of the first studies developed for parcel related data using object-oriented approach for municipalities.

Software evolution and maintenance have received great attention with the steadily increasing complexity of software systems. One recent approach in this field is adaptive programming, which focuses on the evolution of large class hierarchies. Its main objectives are to manage the change in evolutionary systems and to keep costs for adaptive maintenance low. In this thesis we present our experiences with the application of adaptive programming for modeling and implementing the legal advisory system ADONIS. Unlike most other information systems, ADONIS does not simply process data but regulations. Since regulations and laws are frequently a subject to change, we have chosen this domain as the basis for our practical research on adaptive programming. / Die Evolution und Wartung von Software haben wegen der stetig wachsenden Komplexität von Softwaresystemen deutlich an Beachtung gewonnen. Ein aktueller Ansatz auf diesem Gebiet ist die adaptive Programmierung, welche sich auf die Evolution von großen Klassenhierarchien konzentriert. Ihre Hauptziele liegen darin, die wechselnden Anforderungen in evolutionären Systemen zu bewältigen und die Kosten für adaptive Wartung gering zu halten. In dieser Arbeit präsentieren wir unsere Erfahrungen mit der Anwendung der adaptiven Programmierung zur Modellierung und Implementierung des rechtlichen Beratungssystemes ADONIS. Im Gegensatz zu vielen anderen Informationssystemen verarbeitet ADONIS nicht einfach Daten, sondern Vorschriften. Aufgrunddessen, daß Vorschriften und Gesetze häufig geändert werden, haben wir diese Domäne als Grundlage für unsere praktischen Nachforschungen zum Thema adaptive Programmierung ausgewählt.

As e-Health solutions start being integrated into the healthcare system in Stockholm County, the possibility of moving monitored patients out of the hospitals and into their homes increases. Such a change in the healthcare system could require a major redistribution of resources in order to meet possible changes in resource demands. Simulations can be used in order to understand how the healthcare system needs to adapt to handle the relocation of monitored patients. In this thesis project, a simulation platform has been designed and developed to address possible questions posed by this redesign of the healthcare system. By conducting a literary study, it was found that a discrete event- and agent based- hybrid simulation architecture could address the complexity required for such a large simulation environment by simulating across different abstraction levels. The agent based simulation component of the architecture models resources such as nurses, doctors, and patients as agents. A patient agent has a statechart which allows the patient to move between situational states and require interventions depending on a developed illness progression logic and routines. Interventions are modeled as event workflows in the discrete event simulation architecture. These cover most of the relevant interventions in a home monitored patient's life, such as nurse home visits and doctor video consultations. A communication protocol has been defined which will allow this model to communicate with a healthcare facility model. The platform implements a user interface for changing relevant input parameters, such as the amount of patients or doctors, in order to simulate different scenarios. Therefore the provided framework reduces the need for any major reprogramming between model runs. Outputs provided by simulation runs give relevant insights on patient resource usage and logistics management. A method for automatic generation of locations for patient homes and healthcare facilities on Geographic Information Systems open street maps has also been identified but not implemented. A validation process was conducted by allowing experts in the field to test the platform and give feedback on its validity and outputs. The simulation architecture provided by this thesis achieves the objective of modeling flows and resources in a further digitalized healthcare system in Stockholm County.

Modern state-of-the-art equation based object oriented modeling languages such as Modelica have enabled easy modeling of large and complex physical systems. When such complex models are to be simulated, simulation tools typically perform a number of optimizations on the underlying set of equations in the modeled system, with the goal of gaining better simulation performance by decreasing the equation system size and complexity. The tools then typically generate efficient code to obtain fast execution of the simulations. However, with increasing complexity of modeled systems the number of equations and variables are increasing. Therefore, to be able to simulate these large complex systems in an efficient way parallel computing can be exploited. This thesis presents the work of building an automatic parallelization tool that produces an efficient parallel version of the simulation code by building a data dependency graph (task graph) from the simulation code and applying efficient scheduling and clustering algorithms on the task graph. Various scheduling and clustering algorithms, adapted for the requirements from this type of simulation code, have been implemented and evaluated. The scheduling and clustering algorithms presented and evaluated can also be used for functional dataflow languages in general, since the algorithms work on a task graph with dataflow edges between nodes. Results are given in form of speedup measurements and task graph statistics produced by the tool. The conclusion drawn is that some of the algorithms investigated and adapted in this work give reasonable measured speedup results for some specific Modelica models, e.g. a model of a thermofluid pipe gave a speedup of about 2.5 on 8 processors in a PC-cluster. However, future work lies in finding a good algorithm that works well in general. / <p>Report code: LiU-Tek-Lic-2002:06.</p>

Os sistemas computacionais distribuídos aplicados à computação paralela permitem uma melhor relação custo/benefício para a computação paralela. Esses sistemas oferecem a potência computacional adequada às aplicações que não necessitam de uma máquina maciçamente paralela, porém necessitam de uma potência computacional maior que uma máquina seqüencial pode oferecer. P.V.M. (Parallel Virtual Machine) e M.P.I. (Message Passage Inteface) são exemplos de ambiente de paralelos virtuais amplamente discutido na literatura. Tendo em vista a grande utilização desses ambientes tanto em nível acadêmico quanto em níveis comerciais e industriais, torna-se interessante a criação de uma ferramenta que apoie o desenvolvimento de programas para esses ambientes. Poucas são as ferramentas desse tipo que aparecem na literatura; uma delas e que permite ser estendida para dar suporte a tais ambientes é a F.A.P.P. (Ferramenta de Apoio à Programação Paralela). Dentro desse contexto, este trabalho apresenta a modelagem dos ambientes paralelos virtuais segundo a abordagem proposta na definição da F.A.P.P., para que arcabouços de programas P.V.M. e M.P.I possam ser gerados. Essa ferramenta permite a utilização da computação paralela a um maior número de usuários, ou seja, auxiliando os iniciante na confecção dos programa e os experientes na manutenção, além de permitir maior produtividade. Foram realizados estudos visando a validação e a avaliação da ferramenta. Os resultados obtidos demonstram que a ferramenta possui comportamento estável e tem potencial para ser utilizada livremente em ambientes P.V.M. e M.P.I.. / Distributed computing systems applied to parallel computing allow the realisation of a better cost/benefit relation for parallel programming. These systems offer an adequate computing power to those applications which do not require a massively parallel architecture but need such a computer power not available from sequential computers. P.V.M. (Parallel Virtual Machine) and M.P.I. (Message Passing Interface) are good examples of parallel virtual environments being widely discussed in the literature. These virtual environments are broadly used in both academic, commercial and industrial applications, making attractive the development of supporting tools for these parallel programming environments. There are few of such tools available in the literature. F.A.P.P. is one of these tools and it can be extended to support parallel virtual environments. This work addresses the extension of the F.A.P.P. in order to produced P.V.M. and M.P.I. source code. This extension can help a large number of users to develop parallel programs either by giving support for the beginners or by increasing the productivity of the experienced parallel programmers, besides helping in the maintenance phase. The tool produced is tested by means of several examples which show a stable behaviour and that the tool can be easily used in both P.V.M. and M.P.I. environments.

In the last 50 years, a considerable amount of research workhas been completed in the mathematical system theory and theoryof control. Implementation of the results from this researchinto practice has drastically decreased the production costs.Most production processes are highly automated, and the use ofrobots in industry is growing. As far as office, or businessprocesses are concerned, the situation is quite different.Though the office workers and sales personnel have obtainedmuch help from the modern computers, the office and salesprocesses are far behind the production processes on the levelof automation. The computers are used in the office mainly tohelp in performing various activities, e.g., to write a letter,to print an invoice, to complete a transaction, etc. Thecontrol of the business processes in the office remains, to alarge extent, manual. There is a lot to gain if the controlover business processes could be automated, at leastpartially. The material presented in this thesis is aimed to supportthe following hypothesis: "The ideas worked out in the Mathematical system theory formodeling and controlling physical processes can be successfullyused for modeling and controlling business processes." Oneof the main ideas of mathematical system theory is to considera process as a set of valid trajectories in a state space, andthis idea is the keystone for the thesis. The thesis startswith reformulating the state-oriented approach for the domainof business processes to show what kind of sate space can beused in this domain. First, the approach is introducedinformally by means of an example. Next, a possibleformalization adjusted to the properties of business processesis discussed. Then, experimental evidences that the methodsuggested in the thesis can be used in practice are presented.The suggested method is also compared with other methods ofbusiness process modeling to find out the areas where it hasadvantages over the other methods. In the conclusion, theresults are summarized, and plansfor the future are drawn. Most of the material included in the thesis has beenpublished and presented at international conferences. Thecontribution of this thesis consists in organizing the materialin support of the main hypothesis.

This thesis describes work on a new high-level mathematical modeling language and framework called PDEModelica for modeling with partial differential equations. It is an extension to the current Modelica modeling language for object-oriented, equation-based modeling based on differential and algebraic equations. The language extensions and the framework presented in this thesis are consistent with the concepts of Modelica while adding support for partial differential equations and space-distributed variables called fields. The specification of a partial differential equation problem consists of three parts: 1) the description of the definition domain, i.e., the geometric region where the equations are defined, 2) the initial and boundary conditions, and 3) the actual equations. The known and unknown distributed variables in the equation are represented by field variables in PDEModelica. Domains are defined by a geometric description of their boundaries. Equations may use the Modelica derivative operator extended with support for partial derivatives, or vector differential operators such as divergence and gradient, which can be defined for general curvilinear coordinates based on coordinate system definitions. The PDEModelica system also allows the partial differential equation models to be defined using a coefficient-based approach, where PDE models from a library are instantiated with different parameter values. Such a library contains both continuous and discrete representations of the PDE model. The user can instantiate the continuous parts and define the parameters, and the discrete parts containing the equations are automatically instantiated and used to solve the PDE problem numerically. Compared to most earlier work in the area of mathematical modeling languages supporting PDEs, this work provides a modern object-oriented component-based approach to modeling with PDEs, including general support for hierarchical modeling, and for general, complex geometries. It is possible to separate the geometry definition from the model definition, which allows geometries to be defined separately, collected into libraries, and reused in new models. It is also possible to separate the analytical continuous model description from the chosen discretization and numerical solution methods. This allows the model description to be reused, independent of different numerical solution approaches. The PDEModelica field concept allows general declaration of spatially distributed variables. Compared to most other approaches, the field concept described in this work affords a clearer abstraction and defines a new type of variable. Arrays of such field variables can be defined in the same way as arrays of regular, scalar variables. The PDEModelica language supports a clear, mathematical syntax that can be used both for equations referring to fields and explicit domain specifications, used for example to specify boundary conditions. Hierarchical modeling and decomposition is integrated with a general connection concept, which allows connections between ODE/DAE and PDE based models. The implementation of a Modelica library needed for PDEModelica and a prototype implementation of field variables are also described in the thesis. The PDEModelica library contains internal and external solver implementations, and uses external software for mesh generation, requisite for numerical solution of the PDEs. Finally, some examples modeled with PDEModelica and solved using these implementations are presented.