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The construction industry's overall project performance is significantly reduced by numerous interface issues that also hinder its industrialization. Interface Management (IM) is becoming critical to the success of multidisciplinary construction projects. This research deals with three challenging problems associated with IM: 1) how to build a holistic understanding of interface issues for developing all-around IM solutions; 2) how to define and present interface information in a unified, accurate, and efficient way to improve information sharing, coordination, and implementation; and 3) how to resolve interface issues as a whole to optimize IM performance. Comprehensive cause factors of interface issues are investigated from different yet interrelated perspectives. These cause factors allow for the development of an object data model and a systematic IM strategy. The findings of this multi-perspective approach not only add a holistic view of interface issues to the existing body of knowledge but also provide a theoretical base for researchers and practitioners to seek all-around IM solutions. As a key innovation, an object view of interfaces is defined, resulting in a unified way of presenting interface information. This new technique of modeling interfaces as knowledgeable, intelligent, and active objects is far superior to the traditional use of simple relationships. The proposed Interface Object Model (IOM) framework is the first in the literature to present a comprehensive data structure and its dependencies of interface information for object modeling. This can greatly improve the quality and interoperability of modeled interface information. When integrated into a Building Information Modeling (BIM) approach, this technique can significantly enhance BIM capabilities for interface-related coordination, decision-making, operation, and management. As a first application, a systematic model-based IM strategy is conceptually developed, which provides a good foundation for creating an implementation environment for the developed interface model. This strategy aims to resolve interface issues as a whole throughout a complete project process. The multi-perspective approach, the generically structured IOM, and the conceptual, systematic IM strategy all target broad applications. Individually or jointly, they can also be applied to other domains beyond construction. / Ph. D.

The maintenance of legacy software systems that were developed using a procedural design approach is becoming increasingly expensive. The procedural approach is often ill suited for complex systems that need to integrate with other codes. Furthermore, these legacy systems are usually written in FORTRAN, for which there is increasingly less personnel available compared to, say, C++. While it would be desirable to convert these legacy systems into object-oriented codes described in C++, such a conversion process is nontrivial. Currently, the structural design must be manually examined, interpreted, and converted into an object-oriented design described in an object-oriented language. Therefore, the conversion process is likely to introduce numerous new inconsistencies and errors, which degrades the software's quality and increases its costs. The preferred solution would be to automate this conversion process. Automation would promote consistency by eliminating the manual variations in interpretation and implementation. It would therefore maximize the likelihood that the converted code does not introduce new errors relative to the original code. The work presented here automates the conversion process from procedural design described in the FORTRAN77 language into object-oriented design described in the C++ language. It demonstrates the extraction of object-oriented elements using FORTRAN common block structures and FORTRAN subroutine and function-calling hierarchies. The result is a consistent, first-cut converted design, which enhances cohesion within classes and reduces coupling between classes. This result is described in the contemporary, broadly used computer language C++, which integrates with adjacent modules that might still remain procedural and described in FORTRAN. / Master of Science

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

This research is concerned with inheritance as used in object-oriented database. More specifically, partial bi-directional inheritance among classes is examined. In partial inheritance, a class can inherit a proper subset of instance variables from another class. Two subclasses of the same superclass do not need to inherit the same proper subset of instance variables from their superclass. Bi-directional partial inheritance allows a class to inherit instance variables from its subclass. The prototype of an object-oriented database that supports both full and partial bi-directional inheritance among classes was developed on top of an existing relational database management system. The prototype was tested with two database applications. One database application needs full and partial inheritance. The second database application required bi-directional inheritance. The result of this testing suggests both advantages and disadvantages of partial bi-directional inheritance. Future areas of research are also suggested.

M.Sc. (Computer Science) / This report is primarily concerned with highlighting fmdings of a research recently undertaken towards completing the requirements for the M.Sc. degree of 1994 at the Rand Afrikaans University (RAU). The research is aimed at striving to investigate what benefits (if any) exist in Object-Oriented Parallel Systems. The area of research revolves around the Object-Oriented Parallel Paradigm (OOPP) which is currently under development by the author. One primary aim of this research is to investigate numerous current trends in Object-Oriented Parallel Systems and Language Developments with the objective of providing an indication as to whether the Object-Oriented methodology can be (or has been) successfully married with existing Parallel Processing mechanisms. New benefits may come about while attempting to combine these methodologies, and this expectation will also be reflected upon. The Object-Oriented methodology allows a system designer the ability to approach a problem with a good degree of problem space understanding; while Parallel Processing allows the system designer the ability to create extremely fast algorithms for solving problems amenable to Parallel Processing techniques. The question we attempt to answer is whether the Object-Oriented methodology can be successfully married to the Parallel Processing field (whilst maintaining a high degree of benefits encountered in both methodologies) so as to gain the best of both worlds. Certain papers have laid claim to their proposed system encompassing both the Object-Oriented methodology, as well as the Parallel Processing methodology. In view of this fact, we shall furthermore examine papers to see if any of these systems are candidates for successfully marrying Object-Oriented and Parallel Processing into one homogeneous body. Criticism will be given on the shortcomings of unsuccessful candidates. Based on the findings of the research, the report will culminate to the proposal of the Object-Oriented Parallel Paradigm (OOPP). OOPP will speculate on the most probable features that system designers can expect to see in an almost ideal Object-Oriented Parallel System. It is very important at this stage to mention that, at its current state of development, OOPP is only a paradigm; thus OOPP should be viewed merely as an abstract model intended to establish a solid foundation for building more formal Object-Oriented Parallel Methodologies. Furthermore, OOPP is intended to be suitable for present day systems and amenable (possibly with a few minor adjustments) to future systems. The author trusts OOPP to generate sufficient interest to warrant further research being commissioned. In this event, OOPP should be expected to undergo modifications and enhancements...

The object-oriented community is paying increasing attention to techniques for object instance encapsulation and alias protection. Formal techniques for modular verification of programs at the level of objects are being developed hand in hand with type systems and static analysis techniques for restricting the structure of runtime object graphs. Ownership type systems have provided a sound basis for such structural restrictions by being able to statically represent an extensible object ownership hierarchy. However, such structural restrictions may potentially have limitations on cases when more flexible reference structures are desired. In this thesis, we present a different encapsulation technique, called Effect Encapsulation, which confines side effects rather than object references. With relaxed restriction on reference structure, it is able to express certain common object-oriented patterns which cannot be expressed in Ownership Types. From this basis, we also describe a model of Object Validity --- a framework for reasoning about object invariants. Such a framework can track the effect and dependency of method calls on object invariants within an ownership-based type system, even in the presence of re-entrant calls. Moreover, we present an access control technique for protecting object instances. Combined with context variance, the resulting type system allows for a more flexible and useful access control policy, hence is capable of expressing more object-oriented patterns.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, December 2003. / Thesis advisor(s): Bill Ray, Shing Man Tak. Includes bibliographical references (p. 215). Also available online.

There are two popular approaches when developing a software system, the first being System Analysis/System Design (SA/SD) and the second being an Object-Oriented (00) approach. In either approach a poor design inevitably produces a poor application. Thus, being able to evaluate the quality of a systems design is advantageous.The Design Metrics Research Team at Ball State University has developed metrics that measure the quality of software systems. From this research the metric D(G) (a composite of the metrics De and D) has been shown to be very effective when used to determine fault prone modules in a system. However, D(G) has been primarily applied to systems developed using the SA/SD approach. This thesis translated D(G) to an 00 setting and empirically evaluated D(G) to determine if D(G) is a good predictor of error-prone classes. The results indicate that De and Di are indeed good predictors of error-prone classes. Of the classes highlighted by De, 67% had errors, while 100% of the classes highlighted by D; had errors. / Department of Computer Science

The relational model has dominated the database field because of its reduced application development time and non-procedural data manipulation features. It has significant problems, however, including weak integrity constraints. This paper discusses the need for object oriented techniques to improve on these flaws. Three existing DBMS will be discussed: IRIS, ORION, and OZ. / Department of Computer Science