• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.898-902
• /
• 1995

STEP is a neutral model for exchanging CAD modelbetween different CAD systms. The paper presents a laser path contour generation for rapid prototyping originated form STEP format files without using any tools nor libraries for STEP data manipulation. Polygons are generated from every point on the layer of given thickness, which are the intersections of layer plane and edges stored in entity tables. Curves are approximated with polygons whitin segment tolerance limit in order to cover sculptured surfaces. With the advantage of less data loss in direct slicing over STL formats, the system developed in this work shows a good potential to provide data share with various CAD systems including RP data preparation.

• Korean Journal of Computational Design and Engineering
• /
• v.1 no.2
• /
• pp.87-96
• /
• 1996

IGES is a file format which has gained widespread use but has certain limitations such as limited information coverage and ambiguous definitions. In order to overcome the limitations of existing neutral file formats, STEP has been developed as a more comprehensive mechanism for product data exchange by ISO. This paper describes a file translation system between IGES and STEP. In this system, three EXPRESS schemata are defined for IGES, STEP and the translation relationship between IGES and STEP. Object codes are generated from the schemata and linked with file access libraries to IGES and STEP files. The translation was verified by visualization and reverse translation. The system developed in this study can easily applied to translate other file formats because the file structure and translation relationship are defined in EXPRESS - a high level information modeling language.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2003.04a
• /
• pp.434-440
• /
• 2003

The exchange of model design date among heterogeneous CAD systems is a difficult task because each system has different data structures suitable for its own functions. STEP has been able to represent product information as a common computer-interpretable form that is required to remain complete and consistent when the product informant is needed to be exchanged among different computer system. However, STEP has difficult architecture in is representing point, line, curve and vectors of element, more over it can't represent geometry data of feature based models. In this study, a structure of XML document that represents geometry data of feature based models as neutral format has been developed. To use the developed XML document, a Converter has also been developed to exchange modules so that it can exchange feature based data models among heterogeneous CAD systems. Aa for evaluation of the developed XML document and Converter, Solidworks and SolidEdge are selected.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.10a
• /
• pp.392-397
• /
• 2000

A methodology is proposed to share the design information of a gear drive using XML (eXtensible Markup Language). XML is the standard language of the next generation and can be used as a neutral and unique format shared by various Web applications. Since XML is a platform-independent meta-markup language, it is possible to reduce the additional programming efforts for Web applications by using the standardization of technical terminologies. In this study, the structure of design information about gears, shafts, keys and bearings in a gear drive has been made and the terminologies used in the gear drive design process have been authored. The XML DTD(Data Type Definition) for the gear drive design has been declared and the usage of the XML application has been shown.

• Korean Journal of Computational Design and Engineering
• /
• v.6 no.4
• /
• pp.254-262
• /
• 2001

It is not possible to exchange parametric information of CAD (Computer Aided Design) models based on the current version of STEP (Standard leer the Exchange of Product model data). The design intent can be lost during the STEP transfer of CAD models. The ISO Parametrics Group has proposed the SMCH (Solid Model Construction History) schema in June 2000 that includes structures fur exchange of parametric information. This paper proposes the macro parametric approach that is intended to provide capabilities to transfer parametric information. In this approach, CAD models are exchanged in the form of macro files. The macro file contains user commands which are used in the modeling phase. To exchange CAD models using the macro parametric approach, modeling commands of commercial CAD systems are analyzed. Those commands are classified by the grouping method suggested by Bill Anderson. As a neutral file format, a standard modeling commands set has been defined. Mapping relations between the standard modeling commands set and the native modeling commands set of commercial CAD systems are defined.

• Korean Journal of Computational Design and Engineering
• /
• v.6 no.4
• /
• pp.271-276
• /
• 2001

A geometric kernel is the library of core mathematical functions that defines and stores 3D shapes in response to users'commands. We developed a light geometric kernel suitable to develop CAD/CAM application systems. The kernel contains geometric objects, such as points, curves and surfaces and a minimal set of functions for each type but does not contain lots of modeling and handling functions that are useful to create and maintain complex shapes from an idea sketch. The kernel was developed on MS-Windows NT using C++ with STL(Standard Template Library) but it is compatible with UNIX environments. This paper describes the structure of the kernel including several components: base, math, point sequence curve, geometry, translators. The base kernel gives portability to applications and the math kernel contains basic arithmetic and their classes, such as vector and matrix. The geometry kernel contains points, parametric curves, and parametric surfaces. A neutral fie format and programming and document styles are also presented in this paper.

• Speech Sciences
• /
• v.5 no.1
• /
• pp.35-47
• /
• 1999

This paper describes procedures to model and synthesize emotional speech in a multimedia environment. At first, procedures to model the visual representation of emotional speech are proposed. To display the sequences of the images in synchronized form with speech, MSF(Multimedia Speech File) format is proposed and the display software is implemented. Then the emotional speech sinal is collected and analysed to obtain the prosodic characteristics of the emotional speech in limited domain. Multi-emotional sentences are spoken by actors. From the emotional speech signals, prosodic structures are compared in terms of the pseudo-syntactic structure. Based on the analyzed result, neutral speech is transformed into a specific emotinal state by modifying the prosodic structures.

• Journal of Korean Institute of Industrial Engineers
• /
• v.28 no.4
• /
• pp.435-442
• /
• 2002

It is difficult to access and share design data among heterogeneous CAD systems. Usually, different CAD systems exchange the design data using a neutral format such as IGES or STEP. A prototype CAD system which uses a geometric kernel and a commercial database management system has been implemented. The prototype system used the Open Cascade geometric kernel and the commercial object-oriented database ObjectStore. STEP provides the database schema. The database can be accessed from commercial CAD systems such as SolidWorks or Unigraphics. The data access module from a commercial CAD system is developed with the CAD system's native API, ObjectStore API functions, and ActiveX.

• Korean Journal of Computational Design and Engineering
• /
• v.7 no.3
• /
• pp.170-176
• /
• 2002

To exchange CAD data between heterogeneous CAD systems, we generally use a neutral format especially STEP, which is the international standard (ISO-10303) for product model data exchange. AP214 (Application Protocol) for the automotive industry not only takes into account geometry and organizational data, but also provides a classification mechanism for product modeling. When reading a STEP file during a design process that is exported from other CAD systems, it is a burden to a designer to go through the tedious process of removing duplicate or non-manifold entities, adjusting parts, and rearranging text. We analyze the structure of AP214 and develop a healing tool to solve the following problem. Without the assembly information in the Master workspace of CATIA, or to read a STEP file from Pro/Engineer, a designer should do a repetitive process of disintegrating an assembly into parts one by one. We have developed a post-processing tool for STEP AP214 that separates out a part from an assembly model and adjusts superfluous or useless entities using the ACIS kernel.

• International Journal of CAD/CAM
• /
• v.2 no.1
• /
• pp.55-67
• /
• 2002

In many areas of industry, it is desirable to have fast and reliable systems in order to quickly obtain suitable solid models for computer- aided analyses. Nevertheless it is well known that the data exchange process between CAD modelers and CAE packages can require significative efforts. This paper presents an approach for geometrical data exchange through triangulated boundary models. The proposed framework is founded on the use of STL file specification as neutral format file. This work is principally focused on data exchange among CAD modelers and FEA packages via STL. The proposed approach involves the definition of a topological structure suitable for the STL representation and the development of algorithms for topology and geometry data processing in order to get a solid model suitable for finite element analysis or other computer aided engineering purposes. Different algorithms for model processing are considered and their pros and cons are discussed. As a case study, a prototype modeler which supports an exporting filter for a commercial CAE package has been implemented.