High-level Data Model Research Articles

TypeQL: A Type-Theoretic & Polymorphic Query Language

Relational data modeling can often be restrictive as it provides no direct facility for modeling polymorphic types, reified relations, multi-valued attributes, and other common high-level structures in data. This creates many challenges in data modeling and engineering tasks, and has led to the rise of more flexible NoSQL databases, such as graph and document databases. In the absence of structured schemas, however, we can neither express nor validate the intention of data models, making long-term maintenance of databases substantially more difficult. To resolve this dilemma, we argue that, parallel to the role of classical predicate logic for relational algebra, contemporary foundations of mathematics rooted in type theory can guide us in the development of powerful new high-level data models and query languages. To this end, we introduce a new polymorphic entity-relation-attribute (PERA) data model, grounded in type-theoretic principles and accessible through classical conceptual modeling, with a near-natural query language: TypeQL. We illustrate the syntax of TypeQL as well as its denotation in the PERA model, formalize our model as an algebraic theory with dependent types, and describe its stratified semantics.

KG-Hub-building and exchanging biological knowledge graphs.

Knowledge graphs (KGs) are a powerful approach for integrating heterogeneous data and making inferences in biology and many other domains, but a coherent solution for constructing, exchanging, and facilitating the downstream use of KGs is lacking. Here we present KG-Hub, a platform that enables standardized construction, exchange, and reuse of KGs. Features include a simple, modular extract-transform-load pattern for producing graphs compliant with Biolink Model (a high-level data model for standardizing biological data), easy integration of any OBO (Open Biological and Biomedical Ontologies) ontology, cached downloads of upstream data sources, versioned and automatically updated builds with stable URLs, web-browsable storage of KG artifacts on cloud infrastructure, and easy reuse of transformed subgraphs across projects. Current KG-Hub projects span use cases including COVID-19 research, drug repurposing, microbial-environmental interactions, and rare disease research. KG-Hub is equipped with tooling to easily analyze and manipulate KGs. KG-Hub is also tightly integrated with graph machine learning (ML) tools which allow automated graph ML, including node embeddings and training of models for link prediction and node classification. https://kghub.org.

3D cadastral standard definition and development using international standards for Turkey cadastral system

In the last twenty years, cadastral definitions and terminology have been changed all over the world. For this reason, the two dimensional (2D) cadastral terminology has changed to the three dimensional (3D) cadastral context. The 2014 cadastral declarations do not utterly cover the 3D data model. In these contexts, some international standards have been developed for the cadastral process. LADM is to establish a common ontology for rights, responsibilities and restrictions (RRR) affecting the land administration and its geometric components. The other standards are the Infrastructure for Spatial Information in the European Community (INSPIRE) cadastral data themes that are compatible with the LADM data model. However, the INSPIRE cadastral parcels only deal with the geometric part of the cadastral data. Open Geospatial Consortium (OGC) conducts parallel works with ISO / TC 211 committee (ISO/TC 211 is a standard technical committee which is studied areas of digital geographic information and geomatics). OGC within its structure, ISO / TC211 and data standards are similar and compatible. ISO / TC 211 identify high-level and non-direct data models for geographic information producers and users. In this context, the Geo-Marking Language (GML) developed by OGC is a language that enables modelling, storage and sharing of the 3D geometry. Also, it covers the attributes information of geographic objects according to the XML schema. The motivation of the study is to create a standard for a 3D cadastral data model for Turkey by integrating standards with superior and different characteristics. The most important contributions of the study are the evaluation of the Turkish cadastral system within the scope of international standards (especially LADM) and demonstrating the comparability in the international platform. Another contribution is that the legal dimension of the cadastral system is modelled with international standards, and a model proposal is made for 3D cadastral data.

STEP-NC Enabled Machine Tool Digital Twin

Digital twin is a concept redefined with the emergence of Industry 4.0, reflecting the physical characteristics of a certain physical entity into its numerical/digital model in the cyber space. Machine Tool Digital Twin (MTDT) is the application of the digital twin concept on machine tools. MTDT enables thorough analysis of the physical behavior of the machine tool during its operation. This research presented a framework in which a high-level data model, i.e. Standard for the Exchange of Product data compliant for Numerical Control (STEP-NC) is utilized to deliver a rich structured information of the machining process. This data model is machine independent and an international standard. The combination of MTDT and STEP-NC enables establishment of a knowledgebase, which can be utilized for machining process optimization.

FrameSTEP: A framework for annotating semantic trajectories based on episodes

We are witnessing an increasing usage of location data by a variety of applications. Consequently, information systems are required to deal with large datasets containing raw data to build high level abstractions. Semantic Web technologies offer powerful representation tools for pervasive applications. The convergence of location-based services and Semantic Web standards allows an easier interlinking and annotation of trajectories. However, due to the wide range of requirements on modeling mobile object trajectories, it is important to define a high-level data model for representing trajectory episodes and contextual elements with multiple levels of granularity and different options to represent spatial and temporal extents, as well as to express quantitative and qualitative semantic descriptions. In this article, we focus on modeling mobile object trajectories in the context of Semantic Web. First, we introduce a new version of the Semantic Trajectory Episodes (STEP) ontology to represent generic spatiotemporal episodes. Then, we present FrameSTEP as a new framework for annotating semantic trajectories based on episodes. As a result, we combine our ontology, which can represent spatiotemporal phenomena at different levels of granularity, with annotation algorithms, which allow to create instances of our model. The proposed spatial annotation algorithm explores the Linked Open Data cloud and OpenStreetMap tags to find relevant types of spatial features in order to describe the environment where the trajectory took place. Our framework can guide the development of future expert systems in trajectory analysis. It enables reasoning about knowledge gathered from large trajectory data and linked datasets in order to create several intelligent services.

Improving the Efficiency of Large Manufacturing Assembly Plants

Large manufacturing assembly plants with sub assembly lines, sequenced material deliveries, and batch driven primary manufacturing operations often struggle with coordinating their sequenced part manufacturing and kitting operations with the dynamic constraints of the main final assembly line. This paper will outline the high level data model, workflow and use-case scenarios of how the Factboard system integrates into the factory's engineering and transactional data sources as well as how users have been able to use this more accurate, detailed and timely information to make better decisions.

A web-based CAD/CAPP/CAM system compliant with the STEP-NC standard to manufacture parts with general surfaces

In recent decades, there have been important advances related to information technology and manufacturing. Quality and manufacturing productivity have been improved through technologies such as multi-axis machining, high-speed machining, and ultra-precision machining. This led to significant changes in manufacturing companies that were based previously on low-cost standardized products, which started to apply elements of modern manufacturing, to provide responsiveness in a context of flexible demand. Despite advances in manufacturing technologies, the language that computer numerical control machines (CNC) use nowadays is the G-code (ISO 6983 standard), which is a set of instructions that contain the movements that the machine has to perform, without any semantic content regarding the part being processed, causing the loss of much information about the product, making it difficult or impossible to share such information across different areas of the company. In contrast, the ISO 14649 standard (known as STEP-NC) provides a high-level data model related to the manufacturing process, and it has been considered adequate to overcome the problems mentioned above. In this paper is described the methodology and implementation of a CAD/CAPP/CAM system fully compliant with the ISO 14649 standard for the design, process planning, and manufacture of parts having general shapes, and it can be executed by anyone through the Internet. The parts are built with the use of features, which can contain general surfaces, enabling the user to design complex parts. The process planning method considers the possibility of using cutting tools with different diameters for removing different amounts of material from the part. The physical STEP-NC file is generated automatically by the system, and it is used as input to the module that simulates graphically the tool paths for machining the part in a three-axis CNC machine.

STEP-NC based high-level machining simulations integrated with CAD/CAPP/CAM

With the development of manufacturing, numerical control (NC) machining simulation has become a modern tool to obtain safe and reliable machining operations. Although some research and commercial software about NC machining simulations is available, most of them is oriented for G&M code. It is a low-level data model for computer numerical control (CNC), which has inherent drawbacks such as incomplete data and lack of accuracy. These limitations hinder the development of a real simulation system. Whereas, standard for the exchange of product data-compliant numerical control (STEP-NC) is a new and high-level data model for CNC. It provides rich information for CNC machine tools, which creates the condition for an informative and real simulation. Therefore, this paper proposes STEP-NC based high-level NC machining simulations solution integrated with computer-aided design/computer-aided process planning/computer-aided manufacturing (CAD/CAPP/CAM). It turned out that the research provides a better informed simulation environment and promotes the development of modern manufacturing.

Service-oriented, cross-platform and high-level machining simulation

With the development of manufacturing, Web-based numerical control machining simulation has become an important part to realise networked manufacturing and make the training for operators easier. Although some research about it is available, most of them are based on G&M code that has inherent drawbacks such as vendor-specific nature, incomplete data, irreversible data conversions and lack of accuracy. These limitations hinder the development of a truthful simulation system; they are dependent on specific platform and have bad interoperability, which limits their use. Therefore, there is a requirement for high-level data model to be developed and utilised that can assist with accurate simulation for machining processes. In addition, there is also a need to take account of computer heterogeneous environment and online service. To solve these issues, this article proposes service-oriented, cross-platform and high-level machining simulation solution that utilises high-level data such as standard for the exchange of product data and standard for the exchange of product data-compliant numerical control in order to produce an informative and truthful simulation and utilises the proposed browser/server-based model–view–controller-communication-data pattern, Java and Web service technology in order to produce platform-independent and service-oriented machining simulation. The outcome of the research provides a better informed simulation environment, makes the training for operators easier and promotes the development of networked manufacturing.

STEPNCMillUoA: a CNC system based on STEP-NC and Function Block architecture

STEPNCMillUoA is the prototype of a new CNC system that utilises the STEP-NC data model and IEC 61499. STEP-NC provides a high-level data model and enables feature-based machining whereas the enabled layered Function Block architecture simplifies the design of the CNC controller. The architecture layers are responsible for data processing, storage and execution. The object-oriented Model-View-Control design pattern supports the system architecture and the design framework, in which simulation of the machining becomes natural and inherent part of the design process, with seamless transition from simulation to actual machining. This system possesses interoperability, portability, re-configurability and distribution characteristics. The system was tested through simulation and actual machining.

A novel CNC system for turning operations based on a high-level data model

The research work documented in this paper is divided into two parts. In the first part, a generic infrastructure for implementing STEP-NC data models is proposed. The infrastructure illustrates a bidirectional data flow of three different data forms: STEP-NC data, machine specific language, and low-level machine actuation signals. The proposed method utilizes the concepts of modularity and database to harmonize and group machining processes and to manage machining activities. The second part reports on the development of a computer numerical control (CNC) lathe that interprets STEP-NC data into low-level machining instructions. This process was achieved through the development of a software package that can process STEP-NC data and provide an interface with a retrofitted CNC lathe. Tool path information is generated and executed “on-fly” with feedback handled. This new CNC system illustrates the benefits of a novel generation of CNC machine tools that have the capability of being driven by a high-level data model.

TVX - Time and Versions in XML

The proposed work explores the application of temporal and versioning management techniques to the content of XML documents. Recently, many methods have been proposed to address this problem. These methods differ in many aspects, such as which XML objects should be temporalized, thus possessing each one a set of advantages and limitations. We present the TVX model, whose goal is to combine these techniques into a single approach; its united use should supply great flexibility in the temporal treatment of XML documents. This will be accomplished through a high-level data model which can be easily implemented in XML format, along with XQuery-like query and data manipulation languages to handle the temporal XML documents. We also present a case study considering a historic query module over the text of the Brazilian Constitution, that demonstrates the employment of the TVX model in a real-life application.

An approach for handling geographical information in life cycle assessment using a relational database

A new data model has been developed to handle information relevant to site-specific life cycle assessments (LCA). The model is orientated towards GIS-representations of three generalised subsystems; the technical, the environmental and the social subsystems. The technical and environmental systems are mainly linked through flows of energy and matter, which are the causes of environmental impacts, which subsequently is perceived, evaluated and acted upon by the social subsystem. For all three systems important differences, attributable to geographical locations can be determined. With the new data model a possibility to enhance LCA and reach more relevant results emerge due to a higher site specificity. The high level data model is expressed as relations between different entities using the entity relationship (ER) modelling language. An existing LCA-database, SPINE, which is already used by several companies for decision support in product development, can be utilised since the structure of the database supports geographical information. So far, applications with GIS-data are limited, but examples of area specific LCA impact characterisation factors exist.

Modeling the temporal complexities of symptoms.

To analyze the temporal aspects of symptoms, including their temporal uncertainty, in order to develop a high-level conceptual data model representation of this domain. A basic tenet of existing temporal models is that events occur not only relative to a particular date or time, but also relative to the time of some other event. The time an event occurs, particularly when the event is a symptom being recalled by a patient or collected by a busy provider, is frequently incomplete or uncertain, and this uncertainty must also be represented in a temporal data model. The object-oriented modeling technique used in this study is becoming popular among U.S. medical informatics standards developers. A conceptual data model for the temporal aspects of symptom data, including temporal uncertainty, has been developed. The object-oriented modeling approach used enables the temporal objects and attributes defined in this model to be inherited by other medical objects, such as problems. The temporal comparators presented here have previously been defined, and may serve as the basis for standardizing the terms used to describe how one event temporally relates to another. In an attempt to achieve domain completeness, this study concentrated more on developing a model that is highly expressive than on developing one that is easily queried. This trade-off in representation versus "queryability" will require further analysis and may require modifications to the underlying model.

Modeling the Relational Complexities of Symptoms

Realization of the value of reliable codified medical data is growing at a rapid rate. Symptom data in particular have been shown to be useful in decision analysis and in the determination of patient outcomes. Electronic medical record systems are emerging, and attempts are underway to define the structure and content of these systems to support the storage of all medical data. The underlying models upon which these systems are being built continue to be strengthened by a deeper understanding of the complex information they are to store. This report analyzes symptoms as they might be recorded in free text notes and presents a high-level conceptual data model representation of this domain.

Municipal GIS and the enterprise data model

Abstract The City of Scarborough, like many corporations, recently re-evaluated its information technology requirements. The decision was made to model the City's needs in terms of activities and data requirements, concentrating on the Municipal Data Model. First, a two year study was undertaken to understand the business activities of all the disparate components that make up the corporation. This study resulted in individual Information Resource Plans (IRP) for each department. A third year was spent in reconciling the many separate documents and creating a high-level Conceptual Data Model for a Corporate Information System. Of the thirteen broad data groupings, four were assigned to the GIS Group for the design of Detailed Data Models and to populate the resultant databases. The GIS Group, in fact, were to initiate the new Information System for the entire City. The modelling sessions involved hundreds of users from the entire user community in small and large groups, in intensive entity-definition act...

Foundations for object-oriented query processing

A minimal framework for an object-oriented query language standard should (1) include a formal definition of a high-level data model and the syntax and semantics of associated query languages, (2) provide the functionality of relational query languages, and (3) support proofs of correctness of transformations for logical query optimization. In this paper, a high-level conceptual model for object-oriented query processing is discussed; the model includes widely-used structural abstractions such as the isa relationship, associations (properties) between complex objects and complex objects/values, and inheritance of properties. A formal, algebraic query language for the model, inspired by relational algebra, is presented. Operators of the algebra allow queries based on values, queries that manipulate entire objects, and queries that construct new objects from existing objects/values. All queries retain connections to existing database objects, providing logical access paths to data. Each query result is a class, so the algebra has the closure property. The intensional and extensional results of query operators are summarized. Two forms of logical query optimization supported by the query algebra are outlined: algebraic transformations and classifier-based optimizations (optimizations which employ inclusion and exclusion dependencies between classes).

The design of a rotating associative array memory for a relational data base management application

There are significant advantages to tailoring hardware storage devices to support high level data models in very large data bases. A storage device that can assume some of the data selection functions traditionally performed by the CPU can substantially reduce the amount of data to be transferred to the CPU. This reduction together with increased concurrency of CPU and device operation result in increased data rates and lower response times. By designing the device to support one specific data model, greater efficiency can be achieved than in devices designed to be a compromise in their support of several different models. The number and complexity of the functions performed by the device can be drastically reduced, along with its development and production costs. In this paper we describe the design and usage of an associative array memory using a rotating storage device which is tailored to support the relational model of E.F. Codd.