This research develops an object-oriented approach to model airport ground network traffic operations. A generic modeling library is developed as a tool kit to model the basic traffic operations in the airfield using an object-oriented approach. The proposed generic modeling library for airfield operations is a collection of predefined abstract components implemented in the Java object-oriented programming language. Classes are defined and used as the basic components in a variety of airfield operation modeling, simulations, and optimizations. The generic airport modeling framework consists of a set the components that are necessary for modeling the basic activities of airfield traffic operations. By using the multi-threading techniques, components are integrated into the proposed modeling framework. Unlike traditional sequential simulation model, this framework organizes simulation activities into four major groups which are: flight schedule, aircraft movement, time, and animation. Instead of using built-in control logic, the framework adapts an open system policy which gives the flexibility to the end users to incorporate the user-preferred control logic into the end models. Another purpose in this research is to provide a future mechanism to study airfield ground traffic automated control systems with Just-In-Time forecasting and model system performance in a real-time ATC environment. The proposed generic library could be implemented into a Internet/intranet ready application which can query real time information and provide real time advice to pilots and air traffic controllers. This study is one of a few current research projects that are of using multiple threading technique to study traffic operation problems. The proposed generic library is originally implemented with C++ and, in the final stage, with Java, a truly cross-platform object-oriented language. Application written in Java can run on most of the mainstream computer operating systems without modifications. Although the proposed library is for airfield traffic control system, it could also be extended into air traffic control system as well as advanced transportation system. / Ph. D.

This research develops a discrete-event simulation model of the Queston Physician Network using the Visual Simulation Environment (VSE), an object-oriented simulation software program. The Queston Physician Network, a subsidiary of Biological & Popular Culture, Inc., attempts to centralize the administrative, financial, and telecommunication needs of a network of primary care physicians located throughout the United States. The VSE, running on the NeXTSTEP operating system, is a discrete event simulation software package with the capability to tackle the complexities associated with such a network design. The advantages of VSE over other simulation languages include its visualization of objects, domain independence, and object-oriented design and modeling. The objective of the Queston simulation model is to addresses the performance capabilities of the physician network operationally centralized in the Queston Information Center. Additionally, the model could be used to analyze a physician-patient encounter of a generic clinic to identify recommended staffing and scheduling schemes. Object-oriented programming allows the objects in the model to be instantiated at the time of execution. This feature permits the creation of one flexible generic clinic that can be reused to produce several identical clinics at program execution. In this model, one generic, family practice clinic and the Queston Information Center are created. Input data provided by both medical experts and a time study are used. Verification and validation techniques are applied in all phases of the modeling effort. Results using different configurations are presented and recommendations for future research are discussed / Master of Science

<p>This thesis concerns object oriented modelling and automatic generalisation of geographic information. The focus however is not on traditional paper maps, but on screen maps that are automatically generated from a geographical database. Object oriented modelling is used to design screen maps that are equipped with methods that automatically extracts information from a geographical database, generalises the information and displays it on a screen. The thesis consists of three parts: a theoretical background, an object oriented model that incorporates automatic generalisation of geographic information and a case study where parts of the model have been implemented.</p><p>An object oriented model is an abstraction of reality for a certain purpose. The theoretical background describes different aspects that have impact on how an object oriented model shall be designed for automatic generalisation. The following topics are described: category theory, the human ability to recognise visual patterns, previous work in automatic cartographic generalisation, and object oriented modelling.</p><p>A view is here defined to consist of several static levels, or maps, defined at different resolutions. As the user zooms the level that is appropriate for the particular resolution is shown. An object class belongs to one and only one level and has a certain symbolisation. The automatic creation of new objects in a level is discussed as well as the relation between objects in different levels. To preserve topological relations between objects in a level a network structure is formed between all linear objects in a level and objects that might cause conflicts are modelled using dependencies.</p><p>The model is designed for a set of typical geographical object classes such as road, railroad, lake, river, stream, building, built-up area etc. The model is designed to handle information in a scale-range from 1:10 000 to 1:100 000. The model has been implemented for a subset of these classes and tested for an area covering approximatley 60 km².</p>

Both feature and class modeling are used in Software Product Line (SPL) engineering to model variability. Feature models are used primarily to represent user-visible characteristics (i.e., features) of products; whereas class models are often used to model types of components and connectors in a product-line architecture. Previous works have explored the approach of using a single language to express both configurations of features and components. Their goal was to simplify the definition and analysis of feature-to-component mappings and to allow modeling component options as features. A prominent example of this approach is cardinality-based feature modeling, which extends feature models with multiple instantiation and references to express component-like, replicated features. Another example is to support feature modeling in a class modeling language, such as UML or MOF, using their profiling mechanisms and a stylized use of composition. Both examples have notable drawbacks: cardinality-based feature modeling lacks a constraint language and a well-defined semantics; encoding feature models as class models and their evolution bring extra complexity. This dissertation presents Clafer (class, feature, reference), a class modeling language with first-class support for feature modeling. Clafer can express rich structural models augmented with complex constraints, i.e., domain, variability, component models, and meta-models. Clafer supports: (i) class-based meta-models, (ii) object models (with uncertainty, if needed), (iii) feature models with attributes and multiple instantiation, (iv) configurations of feature models, (v) mixtures of meta- and feature models and model templates, and (vi) first-order logic constraints. Clafer also makes it possible to arrange models into multiple specialization and extension layers via constraints and inheritance. On the other hand, in designing Clafer we wanted to create a language that builds upon as few concepts as possible, and is easy to learn. The language is supported by tools for SPL verification and optimization. We propose to unify basic modeling constructs into a single concept, called clafer. In other words, Clafer is not a hybrid language. We identify several key mechanisms allowing a class modeling language to express feature models concisely. We provide Clafer with a formal semantics built in a novel, structurally explicit way. As Clafer subsumes cardinality-based feature modeling with attributes, references, and constraints, we are the first to precisely define semantics of such models. We also explore the notion of partial instantiation that allows for modeling with uncertainty and variability. We show that Object-Oriented Modeling (OOM) languages with no direct support for partial instances can support them via class modeling, using subclassing and strengthening multiplicity constraints. We make the encoding of partial instances via subclassing precise and general. Clafer uses this encoding and pushes the idea even further: it provides a syntactic unification of types and (partial) instances via subclassing and redefinition. We evaluate Clafer analytically and experimentally. The analytical evaluation shows that Clafer can concisely express feature and meta-models via a uniform syntax and unified semantics. The experimental evaluation shows that: 1) Clafer can express a variety of realistic rich structural models with complex constraints, such as variability models, meta-models, model templates, and domain models; and 2) that useful analyses can be performed within seconds.

This thesis concerns object oriented modelling and automatic generalisation of geographic information. The focus however is not on traditional paper maps, but on screen maps that are automatically generated from a geographical database. Object oriented modelling is used to design screen maps that are equipped with methods that automatically extracts information from a geographical database, generalises the information and displays it on a screen. The thesis consists of three parts: a theoretical background, an object oriented model that incorporates automatic generalisation of geographic information and a case study where parts of the model have been implemented. An object oriented model is an abstraction of reality for a certain purpose. The theoretical background describes different aspects that have impact on how an object oriented model shall be designed for automatic generalisation. The following topics are described: category theory, the human ability to recognise visual patterns, previous work in automatic cartographic generalisation, and object oriented modelling. A view is here defined to consist of several static levels, or maps, defined at different resolutions. As the user zooms the level that is appropriate for the particular resolution is shown. An object class belongs to one and only one level and has a certain symbolisation. The automatic creation of new objects in a level is discussed as well as the relation between objects in different levels. To preserve topological relations between objects in a level a network structure is formed between all linear objects in a level and objects that might cause conflicts are modelled using dependencies. The model is designed for a set of typical geographical object classes such as road, railroad, lake, river, stream, building, built-up area etc. The model is designed to handle information in a scale-range from 1:10 000 to 1:100 000. The model has been implemented for a subset of these classes and tested for an area covering approximatley 60 km2. / <p>NR 20140805</p>

Reuse of software designs, experience and components is essential to making substantial improvements in software productivity, development cost, and quality. However, the many facets of reuse are still rarely used in the various phases of the software development lifecycle because of a lack of adequate theories, processes, and tools to support consistent application of reuse concepts. There is a need for approaches including definitions, models and properties of reuse that would provide explicit guidance to a software development team in applying reuse. In particular there is a need to provide abstractions that clearly separate the various functional concerns addressed in a software system. Separating concerns simplifies the identification of the software components that can benefit from reuse and can provide guidance on how reuse may be applied. In this thesis we present an extended model related to the separation of concerns in object-oriented design. The model, called views, indicates how an object-oriented design can be clearly separated into objects and their corresponding interfaces. In this model objects can be designed so that they are independent of their environment, because adaptation to the environment is the responsibility of the interface or view. The view can be seen as expressing the semantics for the 'glue' that joins components or objects together to create a software system. Informal versions of the views model have already been successfully applied to operational and commercial software systems. The objective of this thesis is to provide the views notion with a theoretical foundation to address reuse and separation of concerns. After clearly defining the views model we show the formal approach to combining the objects, interfaces (views), and their interconnection into a complete software system. The objects and interfaces are defined using an object calculus based on temporal logic, while the interconnections among object and views are specified using category theory. This formal framework provides the mathematical foundation to support the verification of the properties of both the components and the composite software system. We then show how verification can be mechanized by converting the formal version of the views model into higher-order logic and using PVS to support mechanical proofs.

This thesis documents the modelling of generic Environmental Control System(ECS) of an aircraft in Modelica by utilizing components from free version of theTTECCS (Technical Thermodynamic Environmental Control and Cooling Systems) library. In doing so, components used for developing ECS from the TTECCS library are mathematically verified with theoretical formula in MATLAB. Selected components are investigated with valid input data to initialize the simulation and verify its behaviors with corresponding available data. Hereinafter, the object-oriented modelling method is used to integrate ECS components to develop a functional system. The main function of ECS is to regulate the pressure and temperature inside the cabin to accepted physiology flight safetylevels. Different types of ECS architecture are presented in this document. An ECS developed here is based on the bootstrap system and consists only one cooling unit comprised with the source, pipes, two heat exchanger, compressor, turbine, temper-ature control valve, pressure control valve, and sinks. Dry air(Ideal gas) is used as a medium in the system. Temperature drop along each component corresponds to available A320 cruise flight data in order to calculate the top level parameter and to initialize the components, subsequently an ECS system. Several systematized methods for Object-oriented modelling and system design were studied and steps are extracted accordingly that suits to initiate the procedurefor this project, which is also presented. Time domain simulation is performed inModelica and Dymola. A simplified control system is built to regulate the system, therefore restrained it as a future work to develop real in-flight condition control system of an ECS.Top level parameters were selected within valid customized ranges for developing a performance map of the components. After generating the map, optimal data from the map were taken to initialize final ECS. The simulation results of the final model is then compared to A320 flight data which is comparable in behavior; this was expected. Above all, simulation environment Modelica and free version of TTECCS library components are reliable to develop ECS in order to investigate ECS components behavior and predict cabin conditions before developing a prototype.

Reuse of software designs, experience and components is essential to making substantial improvements in software productivity, development cost, and quality. However, the many facets of reuse are still rarely used in the various phases of the software development lifecycle because of a lack of adequate theories, processes, and tools to support consistent application of reuse concepts. There is a need for approaches including definitions, models and properties of reuse that would provide explicit guidance to a software development team in applying reuse. In particular there is a need to provide abstractions that clearly separate the various functional concerns addressed in a software system. Separating concerns simplifies the identification of the software components that can benefit from reuse and can provide guidance on how reuse may be applied. In this thesis we present an extended model related to the separation of concerns in object-oriented design. The model, called views, indicates how an object-oriented design can be clearly separated into objects and their corresponding interfaces. In this model objects can be designed so that they are independent of their environment, because adaptation to the environment is the responsibility of the interface or view. The view can be seen as expressing the semantics for the 'glue' that joins components or objects together to create a software system. Informal versions of the views model have already been successfully applied to operational and commercial software systems. The objective of this thesis is to provide the views notion with a theoretical foundation to address reuse and separation of concerns. After clearly defining the views model we show the formal approach to combining the objects, interfaces (views), and their interconnection into a complete software system. The objects and interfaces are defined using an object calculus based on temporal logic, while the interconnections among object and views are specified using category theory. This formal framework provides the mathematical foundation to support the verification of the properties of both the components and the composite software system. We then show how verification can be mechanized by converting the formal version of the views model into higher-order logic and using PVS to support mechanical proofs.

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.

Modeling and simulation form an integral role in the engineering design process. An accurate mathematical description of a system provides the design engineer the flexibility to perform trade studies quickly and accurately to expedite the design process. Most often, the mathematical model of the system contains components of different engineering disciplines. A modeling methodology that can handle these types of systems might be used in an indirect fashion to extract added information from the model.This research examines the ability of a modeling methodology to provide added insight into system analysis and design. The modeling methodology used is bond graph modeling. An investigation into the creation of a bond graph model using the Lagrangian of the system is provided. Upon creation of the bond graph, system analysis is performed. To aid in the system analysis, an object-oriented approach to bond graph modeling is introduced. A framework is provided to simulate the bond graph directly. Through object-oriented simulation of a bond graph, the information contained within the bond graph can be exploited to create a measurement of system efficiency. A definition of system efficiency is given. This measurement of efficiency is used in the design of different controllers of varying architectures. Optimal control of a missile autopilot is discussed within the framework of the calculated system efficiency.