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Danielle L. DeBraccio and Harry S. Delugach, “From Requirements to Software Architectural Style Focusing On Connector Properties”, Intl. Jour. of Interdisciplinary Studies in Computer Science and Engineering, vol. 1, no. 1, pp. 1-35, June 2011. Download PDF

Abstract. Even though the quality of software requirements and software architecture have a significant impact on the success and quality of a software project, few tools exist to support the transition from requirements to architecture. Many desired qualities in a software project that are expressed in the software requirements can be achieved with software architectural styles. This paper proposes an approach towards an automated approach that can help choose an appropriate architectural style given a set of natural language software requirements. The approach, Automated Architecture Scoring Method (AASM), transforms software requirements into a formal model in conceptual graphs which is analyzed for possible software architectural components, and possible properties of those components. AASM then analyzes those properties and develops a recommendation for an architectural style. This paper focuses on using conceptual graphs to guide architectural style selection, with a particular emphasis on software architectural connector properties.

Sandra Carpenter, Harry Delugach, Shamsnaz Virani, Dawn Utley and Julie Fortune, “Reflections and Evolution of an Interdisciplinary Research Team,” Intl. Jour. of Interdisciplinary Studies in Computer Science and Engineering, vol. 1, no. 1, pp. 65-72, June 2011. Download PDF

Abstract. How do interdisciplinary research teams get started and then how do they evolve? This is a brief description of one such team and the lessons that team members learned from each other. Specific examples of research projects are provided to illustrate how team members contributed different skills, abilities, and levels of expertise to the joint endeavor. This paper provides a largely narrative description of one interdisciplinary team's lifespan over a five year period. Some lessons learned are described to potentially impact other teams' efforts.

Harry S. Delugach, "Representing metadata constraints in Common Logic," Intl. Jour. Metadata, Semantics and Ontology, vol. 4, no. 4, pp. 277-286, 2009. This article is available online and openly accessible to all without any restriction except use for commercial purposes in accordance with the policy Inderscience Enterprises Ltd. Download PDF

Abstract. This paper presents a standards-based approach to specifying and reasoning about metadata constraints based on existing metadata registry standards, existing terminologies and Common Logic. The paper introduces Common Logic's basic principles and theory, and applies it to several examples where we might want to reason about metadata constraints. It is our expectation that these additional constraints will be developed by the makers of the metadata for a given data source, and will be included in a metadata registry for exchange with any subscriber to the metadata.

Harry S. Delugach, “Formal Analysis of Workflows in Software Development,” in Handbook of Research on Socio-Technical Design and Social Networking Systems, Brian Whitworth and Aldo de Moor, editors, Information Science Reference Publ., Hershey, PA ( book chapter), 2008, ISBN 978-1-60566-264-0, Chapter 20, pp. 280-297.Copyright 2008, IGI Global, www.igi-global.com. Posted by permission of the publisher. Download PDF

Abstract. Automated tools are often used to support software development workflows. Many of these tools are aimed toward a development workflow that relies implicitly on particular supported roles and activities. Developers may already understand how a tool operates; however, developers do not always understand or adhere to a development process supported (or implied) by the tools, nor adhere to prescribed processes when they are explicit. This chapter is aimed at helping both developers and their managers understand and manage workflows by describing a preliminary formal model of roles and activities in software development. Using this purely descriptive model as a starting point, we evaluate some existing tools with respect to their description of roles in their processes, and finally show one application where process modeling was helpful to managers. We also introduce an extended model of problem status as an example of how formal models can enrich understanding of the software development process, based on the analysis of process roles.

Delugach, Harry S., Editor, ISO/IEC 24707:2007 - Common Logic (CL): a framework for a family of logic-based languages, Intl. Organization of Standards, Geneva, Switzerland, 2007. Download PDF

Harper, Lois W., and Delugach, Harry S., “Using Conceptual Graphs to Represent Agent Semantic Constituents”, in Conceptual Structures at Work: Proc. 12th Intl. Conf. on Conceptual Structures (ICCS 2004), Lecture Notes in Artificial Intelligence, LNAI vol. 3127, Springer-Verlag, Heidelberg, K. E. Wolff, H. D. Pfeiffer and H.S. Delugach, eds., July 2004, pp. 325-338. Download PDF

Abstract. This paper develops two agent knowledge bases in conceptual graph form, one using the KD45 underlying logical model for belief and one without any underlying logical model for belief. Action-attitudes  in the knowledge bases provide contexts that represent the agents’ mental attitude towards, and willingness to act upon information in the knowledge bases. Preconditions for communication acts are also represented in the knowledge bases as well as mental attitude changes following communications. Conceptual graphs are a flexible and extendable form of knowledge representation that is used to capture and represent semantic constituents of communications in a form that may be used by software agents. The knowledge base representations in this paper provide software agents a perspective from which they may reason about the communicating agent’s beliefs and communication actions

Delugach, Harry S., “Towards Building Active Knowledge Systems With Conceptual Graphs,” in Conceptual Structures for Knowledge Creation and Communication: Proc. 11th Intl. Conf. on Conceptual Structures (ICCS 2003), Lecture Notes in Artificial Intelligence, LNAI 2746, Springer-Verlag, Heidelberg, A. de Moor, Wilfried Lex, and Bernhard Ganter, eds., July 2003, pp. 296-308. Download PDF

Abstract: This paper outlines a vision for using conceptual graphs to build active knowledge systems that have the capability to solve practical and com-plex problems. A key ingredient in an active knowledge system is its ability to interact (not just interface) with the real world. Basic features of such systems go beyond logic to include support for data mining, intelligent agents, temporal actors, active sensors, a system for knowledge interchange and finally, support for knowledge-in-the-large

Harper, Lois and Delugach, Harry S., “Using Conceptual Graphs to Capture Semantics of Agent Communication,” in Conceptual Structures for Knowledge Creation and Communication: Proc. 11th Intl. Conf. on Conceptual Structures (ICCS 2003), Lecture Notes in Artificial Intelligence, LNAI 2746, Springer-Verlag, Heidelberg, A. de Moor, Wilfried Lex, and Bernhard Ganter, eds., July 2003, pp. 392-404. Download PDF

Abstract. Agent communication languages such as KQML and the FIPA ACL serve as metalanguages to define software agent message-passing protocols. These metalanguages are incompatible with each other, preventing intercommunication between agents employing different agent communication languages. The primary hindrance to agent intercommunication is the different underlying semantics of the message passing protocols. Conceptual graphs provide a mechanism to bridge this agent communication barrier by representing the semantics of message-passing protocols in the formal representation of conceptual graphs. Semantic content of the KQML tell performative is contrasted with that of the FIPA ACL inform performative and represented in conceptual graphs. The intent is that software agents conversant in CGIF may intelligently translate messages between agents employing different agent communication languages.

Cox, Lisa and Delugach, Harry S. and Skipper, David, "Dependency Analysis Using Conceptual Graphs," Suppl. Proc. 9th Intl. Conf. on Conceptual Structures, July 30 - Aug 4, 2001, Palo Alto, CA, U.S.A. Download PDF

Abstract: Analysis of dependencies between entities is an important part of modeling. Whether the modeling domain is at the enterprise level or at the system or software component level, characterization, representation, and analysis of these dependencies is essential to correctly modeling the domain. For example, it is important to identify and characterize dependencies between both system and software components when trying to determine the extent of and impact of a breach in computer system security or of a malfunction in a component. Analysis of such dependencies is also greatly beneficial in both the requirements and maintenance phases of software engineering. What is needed is a formal characterization of the concept of dependency along with a more formal and unified approach to dependency analysis . This paper introduces the notion of dependency at a general level. In the present literature, an actual definition and characterization of a dependency is usually avoided, and it is difficult to separate the discussion of the dependency from the particular domain of interest. Most of the literature available implies that it is simply “understood” that a dependency can be represented by a directed arc on a graph where the dependent components are the nodes of the graph. Much work in the current literature addresses dependencies in widely varying ways. This paper attempts to formalize both the definition and characterization of a dependency in a unified approach, and then illustrates how dependencies themselves and the effect of those dependencies upon a system can be efficiently modeled using Conceptual Graphs.

H. Delugach and B. Lampkin, "Troika: Using Grids, Lattices and Graphs in Knowledge Acquisition," in Working with Conceptual Structures: Contributions to ICCS 2000, G. Stumme, Ed. Aachen, Germany: Shaker Verlag, 2000, pp. 201-214. Download PDF

Abstract: A knowledge acquisition technique called Troika is presented. Based on a combination of repertory grids, conceptual graphs and formal concept analysis, Troika is a hybrid approach that combines these three approaches. The approaches are introduced and their strengths summarized. Troika's basic algorithms are presented. Some samples from an actual acquisition process are presented to provide some flavor of the approach.

Etzkorn, Letha and Delugach, Harry, "Towards a Semantic Metrics Suite for Object-Oriented Design," Proc.. 34th International Conference on Technology of Object-Oriented Languages and Systems, TOOLS 34 (TOOLS USA), July 30-Aug. 4, 2000, IEEE Computer Society Press, Los Alamitos, CA, 2000, pp. 71-80. Download PDF

Abstract: In recent years much work has been performed in developing suites of metrics that are targeted for object-oriented software, rather than functionally-oriented software. This is necessary since good object-oriented software has several characteristics, such as inheritance and polymorphism, that are not usually present in functionally-oriennted software. However, all of these object-oriented metrics suites have been defined using only syntactic aspects of object-oriented software; indeed, the earlier functionally-oriented metrics were also calculated using onlysyntactic information. All syntactically-oriented metrics have the problem that the mapping from the metric to the quality the metric purposrts to measure, such as the software quality factor "cohesion," is indirect, and often arguable. Thus, a substantial amount of research effort goes into proving that these syntactically-oriented metrics actually do measure their associated quality factors. This paper introduces a new suite of semantically-derived object-oriented mmetrics, which provide a mor e direct mapping from the metric to its associated quality factor than is possible using syntactic metrics. These semantically-derived metrics are calcualted using knowledge-based, program understanding, and natural langauge processing techniques.

Harry S. Delugach, "Repertory Grid Graphs: A Hybrid of Conceptual Graphs and Repertory Grids," Proc. 11th Workshop on Knowledge Acquisition, Banff, Alberta, Canada, 1998. View HTML

Abstract: The purpose of this paper is to introduce an approach to conceptual modeling and acquisition that combines useful features from two well-known knowledge representations: repertory grids and conceptual graphs. Conceptual graphs have the expressive power and reasoning support needed for an effective knowledge-based system, while repertory grids have the cognitive/psychological basis and generality needed to provide excellent elicitation and acquisition facilities. This hybrid approach lends itself to several knowledge acquisition methods, such as using conceptual graphs to build repertory grids, using repertory grids to build conceptual graphs, and using them together to perform heuristic classification. The paper shows how each representation, with only minor adaptation, can accommodate "hooks" into the other so that each may exploit the power of the other in providing efficient knowledge elicitation and acquisition support.

Hinke, Thomas H., and Delugach, Harry S., and Randall P. Wolf, "Protecting Databases From Inference Attacks," Computers and Security, 1997, vol. 16, no. 8, pp. 687-708. Download PDF.

Abstract: This paper presents a model of database inference and a taxonomy of inference detection approaches. The Merlin inference detection system is presented as an example of an automated inference analysis tool that can assess inference vulnerabilities using the schema of a relational database. A manual inference penetration approach is then offered as a means of detecting inferences that involve instances of data or characteristics of groups of instances. These two approaches are offered as practical approaches that can be applied today to address the database inference problem. The final section discusses future directions in database inference research.

Delugach, Harry S., "An Approach To Conceptual Feedback In Multiple Viewed Software Requirements Modeling," Proc. Viewpoints 96: Intl. Workshop on Multiple Perspectives in Software Development, Oct. 14-15, 1996, San Francisco. Download PDF.

Abstract: A multiple viewed requirements technique deals with requirements analysis based on having available diverse multiple descriptions of software requirements. Because these multiple descriptions are often expressed in differing notation schemes based on differing underlying paradigms and methodologies, the problem of consistency and completeness is a significant impediment to obtaining a reliable set of requirements. This paper outlines part of an approach to these multiple-viewed requirements that provides some structure for integrating and validating multiple views. The approach, based on conceptual graphs as a knowledge representation, provides a general and flexible framework within which to acquire and analyze multiple views. As views are acquired, each developer can obtain feedback from others' views within his original notation and thereby gain new insight into his own view.

Wolf, Randall P. and Delugach, Harry S., "Knowledge Acquisition via the Integration of Repertory Grids and Conceptual Graphs," Auxiliary Proceedings, 4th Intl. Conf. on Conceptual Structures, P.W. Eklund, G. Ellis and G. Mann, eds., University of New South Wales, Sydney, Australia, Aug. 19-23, 1996, ISBN 0-7334-1387-0, pp. 108-120.

Abstract: Construction of complex systems requires an understanding of the relation between the problem domain, the problem, and the problem-solving method. Presently, knowledge acquisition systems display limited versatility. By integrating repertory grids with conceptual graphs, an improved ability to handle the problem domain, the problem, and the problem-solving method is attained. Repertory grids may be interfaced with conceptual graphs by translating the meaning of repertory grid constructs into conceptual graphs. A robust translation method is presented along with a demonstrative example of the application of the method to repertory grids. This example suggests the utility of the technique in integrating knowledge from multiple experts.

Delugach, Harry S. and Hinke, Thomas H., "Microanalysis: Acquiring Database Semantics In Conceptual Graphs," Conceptual Structures: Knowledge Representation as Interlingua, P.W. Eklund, G. Ellis and G. Mann, eds., Lecture Notes on Artificial Intelligence LNAI 1115, Springer Verlag, Berlin, 1996, ISBN 3-540-61534-2, pp. 218-228. Presented at ICCS '96, 4th Intl. Conf. on Conceptual Structures, University of New South Wales, Sydney, Australia, Aug. 19-23, 1996.

Abstract: Relational databases are in widespread use, yet they suffer from serious limitations when one uses them for reasoning about real-world enterprises. This is due to the fact that database relations possess no inherent semantics. This paper describes an approach called microanalysis that we have used to effectively capture database semantics represented by conceptual graphs. The technique prescribes a manual knowledge acquisition process whereby each relation schema is captured in a single conceptual graph. The schema's graph can then easily be instantiated for each tuple in the database forming a set of graphs representing the entire database's semantics. Although our technique originally was developed to capture semantics in a restricted domain of interest, namely database inference detection, we believe that domain-directed microanalysis is a general approach that can be of significant value for databases in many domains. We describe the approach and give a brief example.

Randall P. Wolf and Delugach, Harry S., "Knowledge Acquisition via Tracked Repertory Grids," Technical Report TR-UAH-CS-1996-02, Computer Science Dept., Univ. Alabama in Huntsville, 1996. Download PDF

Abstract: One of the more valuable and flexible forms of knowledge acquisition is based upon the use of repertory grids. A useful extension of repertory grids can be created by providing a method of semantically linking associated constructs and repertory grids. This network of grids is a semantic network with nodes consisting of individual repertory grids and links acting as "tracks." A track is a generalization of the laddering process used by repertory grid systems. These linked repertory grids which are acquired using the natural language interface of repertory grids can form an operational definition of a problem solving method.

Delugach, Harry S. and Hinke, Thomas H., "Wizard: A Database Inference Analysis And Detection System," IEEE Trans. Knowledge and Data Engr,., vol. 8, no. 1, pp. 56-66, Special Issue on Secure Database Systems Technology, February, 1996. Download PDF.

Abstract: The database inference problem is a well-known problem in database security and information system security in general. In order to prevent an adversary from inferring classified information from combinations of unclassified information, a database inference analyst must be able to detect and prevent possible inferences. Detecting database inference problems at database design time provides great power in reducing problems over the lifetime of a database. We have developed and constructed a system called Wizard to analyze databases for their inference problems. The system takes as input a database schema, its constituent instances (if available) and additional human-supplied domain information, and provides a set of associations between entities and/or activities that can be grouped by their potential severity of inference vulnerability. A knowledge acquisition process called microanalysis permits semantic knowledge of a database to be incorporated into the analysis using conceptual graphs. These graphs are then analyzed with respect to inference-relevant domains we call facets using tools we have developed. We can determine inference problems within single facets as well as some inference problems between two or more facets. The architecture of the system is meant to be general so that further refinements of inference information subdomains can be easily incorporated into the system.

Delugach, Harry S. and Hinke, Thomas H., "Using Conceptual Graphs To Represent Database Inference Security Analysis," Jour. Computing and Info. Tech., vol. 2, no. 4, pp. 291-307, 1994. Download PDF.

Abstract: This paper describes an approach to database inference analysis based on conceptual graphs. The database inference problem is briefly described. Previous approaches are summarized, followed by a presentation of our inference model, called AERIE. The notions of an inference target class and an inference method class are introduced with examples given. Conceptual graphs are introduced as our means of representing database inference knowledge, as a first step toward analyzing and detecting database inference problems. The classification of inference target classes and the use of conceptual graphs for database inference detection are two important contributions of this paper. Four examples are used to illustrate the approach. We discuss some interesting issues raised by this work, and offer conclusions and our plans for future research.

Delugach, Harry S., "Analyzing Multiple Views Of Software Requirements" in Conceptual Structures: Current Research and Practice, P. Eklund, T. Nagle, J. Nagle and L. Gerholz, eds., Ellis Horwood, New York, pp. 391-410, 1992. Reprinted from Proc. Fifth Annual Wkshop on Conceptual Structures, AAAI-90, Peter Eklund and Laurie Gerholz,, eds., pp. 17-22, Linkoping University, Boston and Stockholm, 1990. Download PDF.

Abstract: This paper describes an application of conceptual graphs to support software requirements development -- the process of determining what software needs exist and how those needs will be filled. As a human knowledge- and experience-based activity, requirements development is an appropriate domain for applying formal models of cognitive structures. This chapter introduces the following contributions to the theory and practice in conceptual graphs: (a) the ability to represent a conceptual graph that changes over time, using a new class of node called a demon node. (b) a structure to partially manipulate informal (external) information (i.e., information not expressed in conceptual graphs), by introducing a special referent form called a private referent. (c) the ability to obtain a conceptual graph representation from a requirements specification written in one of several common notations. (d) a framework using conceptual graphs in the analysis of software requirements that effectively captures the overlap between multiple views.

Delugach, Harry S. and Hinke, Thomas H., "Constrained Lines Of Identity: An Approach To Conditional Joins," Proc. ICCS '94, 2nd Intl. Conf. on Conceptual Structures. University of Maryland, College Park, MD, Aug. 16-19, 1994, pp. 31-44. View Text

Abstract: Conceptual graphs support a notion called a "line of identity" (also called a "co-referent link") that specifies a single concept which is denoted by two or more concept boxes. The multiple concepts can be joined into a single concept (if they are in the same context). This work proposes a richer notion, expressible using existing conceptual graph constructs, that allows finer distinctions to be made about what concepts are allowed to be joined, and also addresses the problem of joining between different contexts. In the course of describing an entire relational database with multiple graphs (one for each database relation). We encountered a problem in joining these graphs into one large graph (the universal join relation); namely, the existence of some instance constraints on joins. In some cases, foreign key attributes in one relation's graph cannot be joined unconditionally with their corresponding attributes in another relation. We describe a new notion, a conditional join, to handle this problem and others as well. We provide a rationale, description and examples of such a join.

Delugach, Harry S. and Hinke, Thomas H. and Chandrasekhar, Asha, "Applying Conceptual Graphs for Inference Detection Using Second Path Analysis," Proc. ICCS93, Intl. Conf. on Conceptual Structures, pp. 188-197, Laval University, Quebec City, Canada, Aug. 4-7, 1993. View Text.

Abstract: Conceptual graphs are applied to a problem in database inference known as second path analysis. A sensitive target is proposed, namely to keep secret that a certain company is working on a certain project. Typically available non-sensitive information is introduced in the form of relational database schemata. These schemata are then expressed as conceptual graphs, followed by a series of joins which are performed revealing the sensitive target. It is shown that conceptual graph representations are able to analyze second path problems and achieve the same results as previous techniques. A new inference path was discovered that had not been identified by previous work.

Polovina, Simon and Delugach, Harry S., "The Economics of Supply and Demand: An Important Challenge For Conceptual Graphs," Proc. ICCS93, Intl. Conf. on Conceptual Structures, pp. 98-108, Laval University, Quebec City, Canada, Aug. 4-7, 1993. View Text. ???

Abstract: Conceptual graphs have been used to model information in many complex domains, but the domain of economics is particularly difficult because its knowledge is based as much on perceptions of people as on physical laws. This paper addresses that problem using as a vehicle one well-known basic economic area: namely, the law of supply and demand. Employing Peirce logic negative contexts, we represent various parts of classical economic theory, e.g., over-supply, over- demand, and equilibrium states. It is shown how tacit knowledge is relevant to the modeling of this information, and why this knowledge requires the conceptual graphs to be built and reviewed by the domain experts directly. Conceptual graph actors are employed to represent relationships between quantities and to represent market forces. Negative contexts are briefly evaluated as a modeling tool. Representing changes in domain assumptions is discussed.

Hinke, Thomas H. and Delugach, Harry S. and Chandrasekhar, Asha. "Layered Knowledge Chunks For Database Inference Detection," Proc. 7th IFIP WG 11.3 Working Conference on Database Security, Huntsville, Alabama, Sept. 12-15, 1993, pp. 276-297.

Delugach, Harry S., "Specifying Multiple-Viewed Software Requirements With Conceptual Graphs," Jour. Systems and Software, vol. 19, pp. 207-224, 1992. View Text.

Abstract: Among all the phases of software development, requirements are particularly difficult to specify and analyze, since requirements for any large software system originate with many different persons. Each person's view of the software requirements may be expressed in a different notation, based on that person's knowledge, experience, and vocabulary. In order to perform a knowledge-based analysis of the requirements in combination, a single knowledge representation must be capable of capturing the information expressible in several existing requirements notations. This paper introduces the notation of conceptual graphs based on semantic networks, that provides a general representation. Four common requirements notations are shown to be expressible using conceptual graphs; with algorithms and examples provided.

Hinke, Thomas H., and Delugach, Harry S., "AERIE: An Inference Modeling and Detection Approach For Databases," Database Security, VI: Status and Prospects, IFIP Transactions, no. A-21, pp. 179-194, B. W. Thuraisingham and C. E. Landwehr, eds., Elsevier Science Publ (North-Holland), Amsterdam, 1993. (reprinted from Proc. 6th IFIP WG 11.3 Working Conference on Database Security, Vancouver, British Columbia, Canada, Aug. 19-21, 1992)

Delugach, Harry S., and Hinke, Thomas H., "AERIE: Database Inference Modeling and Detection Using Conceptual Graphs", Lecture Notes in Artificial Intelligence, no. 754, Chapter 16, Springer-Verlag, Berlin, 1993. (reprinted from Proc. Seventh Annual Workshop 0n Conceptual Graphs, pp. 183-192, New Mexico State University, Las Cruces, New Mexico, July 8-10, 1992).

Abstract: Secure databases are ones in which classified information is protected from access by unauthorized persons. Although the information itself may be secure from direct access, data within the database may be combined along with external data to permit classified data to be inferred. This problem, called the {\em database inference problem}, can be addressed by analyzing a database and its design. An inference detection model based on conceptual graphs is introduced, and explained in terms of different kinds of inference that may be performed. An automated inference analysis tool (IAT) is introduced and its overall architecture described.

Delugach, Harry S., "An Exploration Into Semantic Distance", Lecture Notes in Artificial Intelligence, no. 754, Chapter 9, Springer-Verlag, Berlin, 1993. (reprinted from Proc. Seventh Annual Workshop 0n Conceptual Graphs, pp. 29-37, New Mexico State University, Las Cruces, New Mexico, July 8-10, 1992).

Abstract: The issue of semantic distance has been discussed in several previous papers. Various strategies have been proposed for obtaining some quantitative measure of the similarity between things. In conceptual graph terms, the various approac hes may often be classified according to operations involving the type hierarchy, canonical graph definitions and the context in which particular concepts are found. The proposed paper will discuss the following topics: (a) The meaning of semantic distance, (b) Issues regarding semantic distance measures, (c) Taxonomy of semantic distance measurement schemes, and (d) How to conduct an empirical study of intuitive semantic distance. The purpose of this paper is to suggest an approach for incorporating the notion of semantic distance into the conceptual graph theory, while preserving its meaning as already studied by psychologists, philosophers and cognitive scientists.

Harry S. Delugach, "Dynamic Assertion and Retraction of Conceptual Graphs," Proc. Sixth Annual Workshop on Conceptual Graphs, Eileen C. Way, editor, SUNY Binghamton, Binghamton, New York, pp. 15-26, July 1991, PDF version.

Abstract: This paper proposes an extension to conceptual graphs that captures dynamic aspects of knowledge. This extension is necessary because some kinds of temporal notions are not effectively represented in conceptual graphs containing only concepts, relations and actors. A fundamental extension to conceptual graphs is needed that captures the temporal idea of a process or transformation. A new conceptual graph node type called a demon is proposed, its semantics presented in terms of its relationship to other temporal logics. Examples are provided.

Harry S. Delugach, "A Multiple-Viewed Approach to Software Requirements," Department of Computer Science, University of Virginia, Charlottesville, VA, May, 1991. Ph.D. Dissertation.

Abstract: Most current software requirements development methods center around a single view to which all requirements are made to fit. Such methods are insufficient for requirements that may fall outside the given model, furthermore, they do not take into account important underlying assumptions of the participants. Recent approaches have acknowledged the need for accommodating multiple views of software requirements; however, these approaches have little formal basis with which to perform analysis of the combined requirements. They rely instead on the skill and experience of a human requirements analyst for their effectiveness.

This thesis introduces a knowledge representation approach to multiple viewed software requirements. Using its methodology, participants are free to choose any model they desire for expressing their particular requirements. Each participant's requirements specification is then translated in one common meta-language upon which analysis is performed. The methodology can lead to identification of common elements between the views as well as ambiguities in the views' combination of requirements.

The requirements analyst uses the knowledge representation of conceptual graphs as a meta-language to capture the knowledge from several participants' views. Each set of requirements is then manipulated in graph form to determine the common concepts, called counterparts, between two or more views. The separate graphs can also be combined to form one set of requirements for the entire system.

The combination technique employs an association graph whereby each possible set of counterparts is weighted according to its types and its relationships to other possible counterparts in the requirements. Refinements to the technique take into account a pre-existing general knowledge base. As a result, a numerical comparison is achieved, identifying the strongest possible counterparts and identifying possibly ambiguous counterparts that must be distinguished by feedback from the participants, resulting in additional assumptions, refined requirements, and a further iteration of the methdology.

The thesis also offers a validation framework which can be used to measure the improvements offered by this approach to overall system requirements, and provides a brief example to illustrate the methodology.

Delugach, Harry S., "Multiple Viewed Software Requirements Using Conceptual Graphs," Proc. Fourth Annual Wkshop on Conceptual Graphs, IJCAI-89, Timothy Nagle and Jan Nagle, eds., Aug. 1989, Detroit, Michigan, sec. 4.03

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