Visual Debugging of Object-Oriented Systems with the Unified Modeling Language

The Department of Defense (DoD) is developing a Joint Battlespace Infosphere, linking a large number of data sources and user applications. Debugging and analysis tools are required to aid in this process. Debugging of large object-oriented systems is a difficult cognitive process that requires understanding of both the overall and detailed behavior of the application. In addition, many such applications linked through a distributed system add to this complexity. Standard debuggers do not utilize visualization techniques, focusing mainly on information extracted directly from the source code. To overcome this deficiency, this research designs and implements a methodology that enables developers to analyze, troubleshoot and evaluate object-oriented systems using visualization techniques. It uses the standard UML class diagram coupled with visualization features such as focus+context, animation, graph layout, color encoding and filtering techniques to organize and present information in a manner that facilitates greater program and system comprehension. Multiple levels of abstraction, from low-level details such as source code and variable information to high-level structural detail in the form of a UML class diagram are accessible along with views of the program s control flow. The methods applied provide a considerable improvement (up to 1110%) in the number of classes that can be displayed in a set display area while still preserving user context and the semantics of UML, thus maintaining system understanding. Usability tests validated the application in terms of three criteria software visualization, debugging, and general system usability

An Assessment of PIER Electric Grid Research 2003-2014 White Paper

This white paper describes the circumstances in California around the turn of the 21st century that led the California Energy Commission (CEC) to direct additional Public Interest Energy Research funds to address critical electric grid issues, especially those arising from integrating high penetrations of variable renewable generation with the electric grid. It contains an assessment of the beneficial science and technology advances of the resultant portfolio of electric grid research projects administered under the direction of the CEC by a competitively selected contractor, the University of California’s California Institute for Energy and the Environment, from 2003-2014

Accessible user interface support for multi-device ubiquitous applications: architectural modifiability considerations

The market for personal computing devices is rapidly expanding from PC, to mobile, home entertainment systems, and even the automotive industry. When developing software targeting such ubiquitous devices, the balance between development costs and market coverage has turned out to be a challenging issue. With the rise of Web technology and the Internet of things, ubiquitous applications have become a reality. Nonetheless, the diversity of presentation and interaction modalities still drastically limit the number of targetable devices and the accessibility toward end users. This paper presents webinos, a multi-device application middleware platform founded on the Future Internet infrastructure. Hereto, the platform's architectural modifiability considerations are described and evaluated as a generic enabler for supporting applications, which are executed in ubiquitous computing environments

Feasibility study and analysis of the use of computers to prepare monolithic integrated circuits for GSE Final report

Computerized design of photographic masks for integrated circuit fabricatio

Knowledge From Pictures (KFP)

The old maxim goes: 'A picture is worth a thousand words'. The objective of the research reported in this paper is to demonstrate this idea as it relates to the knowledge acquisition process and the automated development of an expert system's rule base. A prototype tool, the Knowledge From Pictures (KFP) tool, has been developed which configures an expert system's rule base by an automated analysis of and reasoning about a 'picture', i.e., a graphical representation of some target system to be supported by the diagnostic capabilities of the expert system under development. This rule base, when refined, could then be used by the expert system for target system monitoring and fault analysis in an operational setting. Most people, when faced with the problem of understanding the behavior of a complicated system, resort to the use of some picture or graphical representation of the system as an aid in thinking about it. This depiction provides a means of helping the individual to visualize the bahavior and dynamics of the system under study. An analysis of the picture augmented with the individual's background information, allows the problem solver to codify knowledge about the system. This knowledge can, in turn, be used to develop computer programs to automatically monitor the system's performance. The approach taken is this research was to mimic this knowledge acquisition paradigm. A prototype tool was developed which provides the user: (1) a mechanism for graphically representing sample system-configurations appropriate for the domain, and (2) a linguistic device for annotating the graphical representation with the behaviors and mutual influences of the components depicted in the graphic. The KFP tool, reasoning from the graphical depiction along with user-supplied annotations of component behaviors and inter-component influences, generates a rule base that could be used in automating the fault detection, isolation, and repair of the system

An approach to impact analysis in software maintenance

Impact analysis is a software maintenance activity, which consists of determining the scope of a requested change, as a basis for planning and implementing it. After a change request has been specified (change understanding) and the initial part of the system to be changed has been identified (change localization), impact analysis helps to understand consequences of the change on other parts of the system. Induced changes, also named ripple effects, among software components are detected. Most existing approaches perform impact analysis for changes occurring at the code level. In this thesis, concepts developed to perform impact analysis at the code level are applied to trace changes occurring at the design level. The method consists of proposing an activity model addressing the different steps of impact analysis and a data model on which propagations of changes can be traced. The method is validated with a case study applied to a system from the aerospace field. The tools we developed on PCTE help for consistency checks in HOOD based designs during editing. Our data-model based on an Entity Relationship notation describes a way to model HOOD diagrams in PCTE and further on to propagate changes on the repository. Examples chosen address the design phase of a simple engine system. We show that addressing modifications at a higher level of abstraction than the code eases understanding and localization of changes. It also limits the propagation of ripple effects (i.e., unexpected behaviour of the system) by detecting secondary changes at an earlier stage

Inverse software configuration management

Software systems are playing an increasingly important role in almost every aspect of today’s society such that they impact on our businesses, industry, leisure, health and safety. Many of these systems are extremely large and complex and depend upon the correct interaction of many hundreds or even thousands of heterogeneous components. Commensurate with this increased reliance on software is the need for high quality products that meet customer expectations, perform reliably and which can be cost-effectively and safely maintained. Techniques such as software configuration management have proved to be invaluable during the development process to ensure that this is the case. However, there are a very large number of legacy systems which were not developed under controlled conditions, but which still, need to be maintained due to the heavy investment incorporated within them. Such systems are characterised by extremely high program comprehension overheads and the probability that new errors will be introduced during the maintenance process often with serious consequences. To address the issues concerning maintenance of legacy systems this thesis has defined and developed a new process and associated maintenance model, Inverse Software Configuration Management (ISCM). This model centres on a layered approach to the program comprehension process through the definition of a number of software configuration abstractions. This information together with the set of rules for reclaiming the information is stored within an Extensible System Information Base (ESIB) via, die definition of a Programming-in-the- Environment (PITE) language, the Inverse Configuration Description Language (ICDL). In order to assist the application of the ISCM process across a wide range of software applications and system architectures, die PISCES (Proforma Identification Scheme for Configurations of Existing Systems) method has been developed as a series of defined procedures and guidelines. To underpin the method and to offer a user-friendly interface to the process a series of templates, the Proforma Increasing Complexity Series (PICS) has been developed. To enable the useful employment of these techniques on large-scale systems, the subject of automation has been addressed through the development of a flexible meta-CASE environment, the PISCES M4 (MultiMedia Maintenance Manager) system. Of particular interest within this environment is the provision of a multimedia user interface (MUI) to die maintenance process. As a means of evaluating the PISCES method and to provide feedback into die ISCM process a number of practical applications have been modelled. In summary, this research has considered a number of concepts some of which are innovative in themselves, others of which are used in an innovative manner. In combination these concepts may be considered to considerably advance the knowledge and understanding of die comprehension process during the maintenance of legacy software systems. A number of publications have already resulted from the research and several more are in preparation. Additionally a number of areas for further study have been identified some of which are already underway as funded research and development projects