XML-based Data Processing in Network Supported Collaborative Design

In the course of network supported collaborative design, the data processing plays a very vital role. Much effort has been spent in this area, and many kinds of approaches have been proposed. Based on the correlative materials, this paper presents extensible markup language （XML） based strategy for several important problems of data processing in network supported collaborative design, such as the representation of standard for the exchange of product model data （STEP） with XML in the product information expression and the management of XML documents using relational database. The paper gives a detailed exposition on how to clarify the mapping between XML structure and the relationship database structure and how XML-QL queries can be translated into structured query language （SQL） queries. Finally, the structure of data processing system based on XML is presented.

A RESTful proxy and data model for linked sensor data

The vision of a Digital Earth calls for more dynamic information systems,new sources of information,and stronger capabilities for their integration.Sensor networks have been identified as a major information source for the Digital Earth,while Semantic Web technologies have been proposed to facilitate integration.So far,sensor data are stored and published using the Observations&Measurements standard of the Open Geospatial Consortium(OGC)as data model.With the advent of Volunteered Geographic Information and the Semantic Sensor Web,work on an ontological model gained importance within Sensor Web Enablement(SWE).In contrast to data models,an ontological approach abstracts from implementation details by focusing on modeling the physical world from the perspective of a particular domain.Ontologies restrict the interpretation of vocabularies toward their intended meaning.The ongoing paradigm shift to Linked Sensor Data complements this attempt.Two questions have to be addressed:(1)how to refer to changing and frequently updated data sets using Uniform Resource Identifiers,and(2)how to establish meaningful links between those data sets,that is,observations,sensors,features of interest,and observed properties?In this paper,we present a Linked Data model and a RESTful proxy for OGC’s Sensor Observation Service to improve integration and inter-linkage of observation data for the Digital Earth.

StarFL - a modularised metadata language for sensor descriptions

An ever-increasing number of sensor resources are being exposed via the World Wide Web to become part of the Digital Earth.Discovery,selection and use of these sensors and their observations require a robust sensor information model,but the consistent description of sensor metadata is a complex and difficult task.Currently,the only available robust model is SensorML,which is intentionally designed in a very generic way.Due to this genericness,interoperability can hardly be achieved without the definition of application profiles that further constrain the use and expressiveness of the root language.So far,such SensorML profiles have only been developed up to a limited extent.This work describes a new approach for defining sensor metadata,the Starfish Fungus Language(StarFL)model.This language follows a more restrictive approach and incorporates concepts from the recently published Semantic Sensor Network Ontology to overcome the key issues users are experiencing with SensorML.StarFL defines a restricted vocabulary and model for sensor metadata to achieve a high level of interoperability and a straightforward reusability of sensor descriptions.

STEP AP 242 Managed Model-based 3D Engineering:An Application Towards the Automation of Fixture Planning

Fixture design and planning is one of the most important manufacturing activities, playing a pivotal role in deciding the lead time for product development. Fixture design, which affects the part-quality in terms of geometric accuracy and surface finish, can be enhanced by using the product manufacturing information(PMI) stored in the neutral standard for the exchange of product model data(STEP) file, thereby integrating design and manufacturing. The present paper proposes a unique fixture design approach, to extract the geometry information from STEP application protocol(AP) 242 files of computer aided design(CAD) models, for providing automatic suggestions of locator positions and clamping surfaces. Automatic feature extraction software "FiXplan", developed using the programming language C#, is used to extract the part feature, dimension and geometry information. The information from the STEP AP 242 file is deduced using geometric reasoning techniques, which in turn is utilized for fixture planning. The developed software is observed to be adept in identifying the primary, secondary, and tertiary locating faces and locator position configurations of prismatic components. Structural analysis of the prismatic part under different locator positions was performed using commercial finite element method software, ABAQUS, and the optimized locator position was identified on the basis of minimum deformation of the workpiece.The area-ratio(base locator enclosed area(%)/work piece base area(%)) for the ideal locator configuration was observed as 33%. Experiments were conducted on a prismatic workpiece using a specially designed fixture, for different locator configurations. The surface roughness and waviness of the machined surfaces were analysed using an Alicona non-contact optical profilometer. The best surface characteristics were obtained for the surface machined under the ideal locator positions having an area-ratio of 33%, thus validating the predicted numerical results. The efficiency, capability and applicability of the developed software is demonstrated for the finishing operation of a sensor cover – a typical prismatic component having applications in the naval industry, under different locator configurations.The best results were obtained under the proposed ideal locator configuration of area-ratio 33%.

Geological applications using geospatial standards-an example from OneGeology-Europe and GeoSciML

The Geoscience Markup Language(GeoSciML)has been developed to enable the interchange of geoscience information,principally that portrayed on geological maps as well as boreholes.A GeoSciML testbed was developed both to test the implementation of the data model and its application in web services.The OneGeology-Europe project aims to use the GeoSciML data model,and build on the experience of the GeoSciML testbed,in implementing a geoportal for a harmonised geological map of Europe at 1:1 million scale.This involves the integration of web services from 20 participating organisations.An important objective of OneGeology-Europe is to contribute to Infrastructure for Spatial Information in the European Community(INSPIRE),both through the development of a geological data specification and the use of the INSPIRE technical architecture.GeoSciML and the OneGeology-Europe project are also steps towards incorporating geoscience data into a Digital Earth.Both the development of GeoSciML and the implementation of web services for GeoSciML and OneGeology-Europe,have followed a standards-based metho-dology.The technical architecture comprises a geoportal providing access to a Catalogue Service for the Web for metadata describing both the data and services available.OneGeology-Europe will provide bothWeb Map Services view andWeb Feature Services download services,which aim to be compliant with the INSPIRE implementing rules.

The application of open standards to enhance the interoperability of geoscience information

We can adequately study broad global issues and policies only by taking geosciences into account.Our research and decision-making must share and make effective use of interdisciplinary data sources,models,and processes.Noninteroperability impedes sharing of data and computing resources.Standards from the Open Geospatial Consortium(OGC)and other organizations are the basis for successfully deploying a seamless,distributed information infrastructure for the geosciences.Several specifications now adopted by the OGC consensus process are the result of OGC interoperability initiatives.The OGC standards,deployment architectures,and interoperability initiatives are described showing how the OGC standards baseline has been developed and applies to the geosciences.

Mediating among GeoSciML resources

Integration of data across multiple independently developed data sources can be challenging due to a variety of heterogeneities that exist across such systems.Data mediation technologies provide approaches for overcoming these heterogeneities.Standards such as Geoscience Markup Language can address some of the heterogeneity issues by providing schema standards which sources can adhere to.This article addresses the issue of semantic heterogeneity across information resources by using domain ontologies and registering schema elements and data values to such ontologies.Registering data to ontologies provides a powerful search and data integration capability across disparate geoscience information resources.

Study on Distributed Knowledge Information System for Product Design

To overcome the limitations of commercial CAD and handbook form of knowledge expression, the Distributed Knowledge Information System (DKIS) for product design is proposed. The structure of DKIS and the key issues in its implementation are introduced; the method of knowledge store and transfer of DKIS is discussed. The mechanism of knowledge representation, acquisition and utilization, based on Internet network, is achieved. Based on the concept of function driven, integrated Artificial Neural Networks and Active Server Pages techniques, transplanting the trained ANN into DKIS system, a new method for retrieving knowledge in DKIS over Internet is achieved. Finally, a prototype of DKIS is developed to demonstrate the feasibility of the structure and constructional method of DKIS. The work pro-vides a scheme for speed knowledge acquisition and shortens the cycle of product development.

STEP-based Feature Recognition System for B-spline Surface Features

The geometrical and topological information of 3D computer aided design （CAD） models should be represented as a neut- ral format file to exchange the data between different CAD systems. Exchange of 3D CAD model data implies that the companies must exchange complete information about their products, all the way from design, manufacturing to inspection and shipping. This informa- tion should be available to each relevant partner over the entire life cycle of the product. This led to the development of an international standard organization （ISO） neutral format file named as standard for the exchange of product model data （STEP）. It has been ob- served from the literature, the feature recognition systems developed were identified as planar, cylindrical, conical and to some extent spherical and toroidal surfaces. The advanced surface features such as B-spline and its subtypes are not identified. Therefore, in this work, a STEP-based feature recognition system is developed to recognize t--spline surface features and its sub-types from the 3D CAD model represented in AP203 neutral file format. The developed feature recognition system is implemented in Java programming language and the product model data represented in STEP AP203 format is interpreted through Java standard data access interface （JSDAI）. The developed system could recognize B-spline surface features such as B-Spline surface with knots, quasi uniform surface, uniform surface, rational surface and Bezier surface. The application of extracted B-spline surface features information is discussed with reference to the toolpath generation for STEP-NC （STEP AP238）.

Feature Analysis of STEP Application Protocol and its Application

This paper uses semantic data modelling and CAD/CAPP/CAM integration to analyze the features defined in the STEP AP214, its characteristics of definition and distribution, and its influence on the complexity of CAD/CAPP/CAM application integration. A framework is developed for applications of CAD/CAPP/CAM integration based on the STEP to reduce the complexity of integration implementation. Two application program interfaces (API), namely, application protocol API and application API, are developed. The frameworks hierarchy structure and the application program interfaces between the layers make the integration of applications easier.