OkJoon Kim

An Ontology Mapping Application Using a Shared Ontology Approach and a Bridge Ontology

This paper presents our continuing work to develop methods to exchange product knowledge in the semantic level in the CAD/CAE domains. We present an approach based on a shared ontology, in which a higher level of ontologies are shared among lower levels of ontologies. Key mapping strategies, such as Equivalency, Attribute Similarity, Composition Similarity, and Inheritance Similarity are defined to map concepts and properties defined in a product design domain and an assembly simulation domain. In addition, a Bridge Ontology is designed to store information obtained from mapping processes and construct a link between different knowledge repositories. An Ontology Mapping Application (OMA) which brings together all these elements has been designed and implemented. It is a Java-based application that allows the user to load source and target ontologies, calculate concept and property similarities between them, display the mapping results, and output a corresponding Bridge Ontology.Copyright

Ontology-Driven Integration of CAD/CAE Applications: Strategies and Comparisons

In this paper we present a detailed exploration of ontology-driven approaches and strategies for integrating product data between CAD/CAE applications. We structure the ontology model into three layers: General Domain Ontology, Domain Specific Ontology, and Application Specific Ontology. In particular, Application Specific Ontologies are built for PRO/E, CATIA, and a virtual assembly design tool called VADE. This allows the integration processes to be demonstrated for a) two applications in the common domain of product design, and b) two applications in different domains, one in the product design domain and the other in an assembly simulation domain. In addition, these ontology-driven strategies are compared with two other approaches. The first study focuses on the knowledge modeling aspect and compares the ontology approach with a standard modeling language, UML. The second study focuses on data integration and translation aspect and compares the ontology-driven approach with a traditional one. It is concluded that an ontology-driven approach is superior for solving heterogeneous data problems involving multiple applications by managing data on semantic level.Copyright

Semantic Applications Enabling Reasoning in Product Assembly Ontologies—Moving Past Modeling

In this paper, the authors postulate an approach to introduce reasoning capabilities into ontologies in the product assembly domain in order to truly exploit these logic-based and formal representations for product data. A model containing semantic applications with multiple reasoning units in logic reasoning layer of a layered semantic application architecture is proposed. Retrieval specifications and inference rules in SWRL/SQWRL are defined in these reasoning units. Besides, local-based user interfaces have been developed to allow product engineers to submit reasoning tasks and view querying retrievals or inference results. The approach and semantic applications are illustrated with two case studies in the product assembly domain. It is demonstrated that this approach not only enables existing product data to be queried and retrieved but also enables new product data, which is not explicitly expressed in the ontology models, to be derived. It is concluded that the reasoning mechanism exploits and extends the semantic representation made possible through the ontology and thus holds promise for improved knowledge discovery and understanding.

Querying and Reasoning With Product Engineering Ontologies: Moving Past Modeling

Much of the work in ontologies for product engineering has focused on the modeling of these ontologies. A key characteristic of an ontology model is that it uses a logicbased and formal specification to represent the information model, thus allowing querying and reasoning. In order to take advantage of this, we seek to move past ontology modeling and focus on developing meaningful reasoning mechanisms that are applicable for the domain of product engineering – a) to allow the user to make basic inferences such as checking consistency for definitions of concepts, b) to query and retrieve existing product data information, and c) to derive new product data information not explicitly expressed in knowledge bases. A typical semantic application architecture consisting of knowledge base layer, logic reasoning layer, and application interface layer is adopted. Reasoning units are deployed in the logic reasoning layer of this architecture. These reasoning units act on the knowledge base for product engineering, specifically, the domain of product assembly constraint. SWRL & SQWRL are used to define the retrieval specifications and inference rules. User interfaces are also developed to help users submit the reasoning tasks, view the results, and thus assess the knowledge base indirectly and transparently. It is concluded that the reasoning mechanism exploits and extends the semantic representation made possible through ontology and holds promise for improved knowledge discovery and understanding.

iTrain: Ontology-Based Integration of Information and Methods in Computer-Based Training (CBT) and Immersive Training (IMT) for Assembly Simulations

Training for assembly simulations can be provided using a wide range of technologies — from a simple computer-based training (CBT) approach to a complex immersive training (IMT) approach. The CBT approach allows user interactions through traditional keyboard and mouse while the IMT approach immerses the user in a virtual environment for a more realistic experience. Typically, for a particular scenario, tools for each of these are developed completely independently. Consequently, there is much duplication of data and effort and a lack of synchronization between them. In this paper, we focus on ontologies for the assembly simulation and training domain. Ontologies provide an opportunity to capture and manage common data and map concepts from one application to another in a logical and measured manner. Methods are developed to enable knowledge in these ontologies to be used and shared in a comprehensive and effective manner between CBT and IMT tools. Both tools are also well integrated with the Sharable Content Object Reference Model (SCORM) so that the progress during training can be recorded, tracked and evaluated by Learning Management System (LMS).Copyright

Online Semantic Knowledge Management for Product Design Based on Product Engineering Ontologies

This paper formulates an approach to use the semantic web for knowledge management in the product design domain to provide enhanced capabilities of authoring/updating, querying/reasoning, searching, and visualization of information. Engineering has unique challenges, due to the pervasive use of CAD models and underlying interoperability and integration issues. The authors propose a distributed model composed of a host hybrid-data repository, external public linked data sources, a semantic data management engine, and a web-based user interface layer. The hybrid-data repository consists of ontologies to preserve knowledge for the product design domain and a conventional product data base to utilize legacy design data. Near full integration with a web based environment is achieved. The importance of accessing product related CAD data that has been instantiated in ontology models, querying them, and then displaying the data on a web interface in real time with other legacy data, such as hand sketches and notes that have been scanned and relevant information from conventional rational databases public linked data sites, is a useful and transformational capability. The system clearly facilitates design and information management beyond traditional CAD capabilities and creates a foundation for important capability improvements in the domain.

A Unified Strategy to Integrate Information and Methods Across Multiple Training Environments for Assembly Simulations

Training for assembly simulations can be provided using a wide range of technologies from a simple computer-based training (CBT) approach to a complex virtual reality (VR)-based immersive training (IMT) approach. The CBT approach allows user interactions through traditional keyboard and mouse applications, while the IMT approach immerses the user in a virtual environment for a more realistic experience. Typically, for a particular scenario, tools and applications for each of these approaches are developed independently. Consequently, there is much duplication of data and effort, and a lack of synchronization between them. This paper focuses on an integrated approach with support from ontologies to address this problem. Ontologies provide an opportunity to capture and manage common data and map concepts from one application to another in a logical and measured manner. Methods are developed to enable knowledge in these ontologies to be used and shared in a comprehensive and effective manner between CBT and IMT tools. The key contribution of this work is that the ontologies instantiating concepts and properties for the training domain are used effectively among different training tools to deal with common and disparate characteristics between them.

Knowledge Representation and Ontology Mapping Methods for Product Data in Engineering Applications

This work seeks to create a semantic approach that uses ontologies for sharing knowledge related to product data in CAD/CAE applications and for integrating the design evaluation information that these applications individually provide. Our overall approach is coined OADE, Ontology-based Adaptive Design Evaluation. This paper reports on a piece of our ongoing work in this area. The key contributions of this paper include methods for the design of knowledge representation in product design and analysis, population of product data semantics, creation of ontology mapping methods and mapping representations, and mapping of product data semantics to the target application. The mapping method finds matching concepts between different ontologies based on three basic concept relation types: composition, inheritance, and attribute. A prototype implementation is being created using technologies such as OWL (representation tool), Jena (ontology builder), and Protege (ontology editor) to demonstrate the approach for integrating a parametric CAD system, custom virtual assembly application, and an ergonomics engineering application. An example is given in this paper to illustrate how this approach can help integration between a product design application and an assembly simulation analysis application. The significance of this work is that it will provide the capability to create, share, and exchange knowledge for solving design evaluation challenges involving multiple applications and multiple viewpoints. A design decision can thus be described using the common concepts across the diverse entities.Copyright

An Ontology-Based Online Community to Maintain Engineering Knowledge in a Training Domain

The research presented in this paper seeks to develop an ontology-based online community for knowledge exchange between expert engineers and new engineers. We call this community CREEK (Community for Retention of Engineering dEsign Knowledge). This paper seeks to develop methods and tools related to knowledge acquisition, knowledge modeling, knowledge management, and knowledge presentation that can support activities in this community in engineering design and training domains. An important consideration is to design and deploy the online community and the underlying ontology model such that they will not exist in isolation but will be connected to a product data ontology and a training ontology. In our previous work engineering knowledge related to product data in engineering design and assembly has been modeled. In this work procedural knowledge and knowledge in the training domains related to these procedures are also modeled and populated using ontologies. We have designed an architecture that will allow the ontology of the on-line community to tap into the engineering knowledge from these two supporting domains. In addition, there is a connection the other way too. The online community also allows new knowledge to be captured from experts and be (semi-)automatically transferred to product design and training domains.Copyright

Enhancing a Traditional Ergonomics Tool With Capabilities and Algorithms From Immersive Environments

This paper presents our continuing work in approaches to link traditional, commercially available ergonomics evaluation tools with virtual environment tools for providing enhanced capabilities for engineering design. Ergonomic evaluation tools in engineering design are fairly mature and are used in important and specific ways to analyze human model postures in industry. The promising capabilities of immersive environment tools such as realistic environments and interactions, constraint-based modeling, and physically-based modeling are attractive to industry but have so far been available only in environments separate from the traditional ergonomics analysis tools. Our research seeks to create well-integrated synergistic approaches that will complement traditional ergonomics tools with a careful assimilation of capabilities and algorithms from a virtual environment. The information exchange, representations, communication, and computational issues involved in achieving this connectivity are discussed in this paper. We demonstrate this functionality between a commercial ergonomics tool and an immersive assembly system. It is anticipated that this synergy between an ergonomics tool and a virtual environment will lead to breakthroughs and ease of use benefits similar to those that have now been obtained by the close integration of CAD and virtual environments.Copyright