The GPR system: An architecture for integrating active and deductive rules on complex database objects

The authors address the problem of providing a homogeneous framework for integrating, in a database environment, active rules, which allow the specification of actions to be executed whenever certain events take place, and deductive rules, which allow the specification of deductions in a logic programming style. Actually, it is widely recognized that both kinds of rules enhance the capabilities of database systems since they provide very natural mechanisms for the management of various important activities (e.g., knowledge representation, complex data manipulation, integrity constraint enforcement, view maintenance). However, in spite of their strong relationship, little work has been done on the unification of these powerful paradigms. They present a rule-based language with an event-driven semantics that allows programmers to express both active and deductive computations. The language is based on a new notion of production rules whose effect is both a change of state and an answer to a query. By using several examples, they show that this simple language schema allows one to uniformly define different computations on data, including complex data manipulations, deductive evaluations, and active rule processing. They define the semantics of the language and then describe the architecture of a preliminary implementation of the language. Finally, they report on the application and experience of using the language.

Lazy narrowing with simplification

Datalog is extended to incorporate single-valued “data functions”, which correspond to attributes in semantic models, and which may be base (user-specified) or derived (computed). Both conventional and stratified datalog are considered. Under the extension, a datalog program may not be consistent, because a derived function symbol may evaluate to something which is not a function. Consistency is shown to be undecidable, and is decidable in a number of restricted cases. A syntactic restriction, panwise consistency , is shown to guarantee consistency. The framework developed here can also be used to incorporate single-valued data functions into the Complex Object Language (COL), which supports deductive capabilities, complex database objects, and set-valued data functions. There is a natural correspondence between the extended datalog introduced here, and the usual datalog with functional dependencies. For families Φ and Γ of dependencies and a family of datalog programs Λ, the Φ-Γ implication problem for Λ asks, given sets F ⊆ Φ and G ⊆ Γ and a program P in Λ, whether for all inputs I, I @@@@ F implies P(I) @@@@ G. The FD-FD implication problem is undecidable for datalog, and the TGD-EGD implication problem is decidable for stratified datalog. Also, the Ø-MVD problem is undecidable (and hence also the MVD-preservation problem).

Data mining is the discovery of knowledge and useful information from the large amounts of data stored in databases. The emerging data mining tools and systems lead to the demand of a powerful data mining query language. The concepts of such a language for relational databases are discussed before. With the increasing popularity of object-oriented databases, it is important to design a data mining query language for such databases. The main objective of this paper is to propose an Object Data Mining Query Language (ODMQL) for object-oriented databases as an extension to the Object Query Language (OQL) proposed by the Object Data Management Group (ODMG) as a standard query language for object-oriented databases. The proposed language is implemented as a feature of an experimental object-oriented database management system that is developed as a testbed for research issues of object-oriented databases.

A familial specification language for database application systems

Knowledge intensive applications require an intelligent environment, which can perform deductions in response to user queries or events that occur inside or outside of the applications. For that, we propose a fuzzy active object-oriented database for modeling knowledge intensive applications. In that, we incorporate fuzziness within the event, condition and action parts of an active rule. We consider deductive rules as special cases of active rules so that deductive queries are handled using abstract kind of events. We also introduce a model for fuzzy inferencing of fuzzy active rules where we develop a model for scenario concept. We use a Fuzzy Petri Net model for fuzzy rule-based inference.

In this paper we present R-DEVICE, a deductive rule language for reasoning about RDF metadata. R-DEVICE includes features such as normal and generalized path expressions, stratified negation, aggregate, grouping, and sorting, functions. The rule language supports a second-order syntax, where variables can range over classes and properties. Users can define views which are materialized and, optionally, incrementally maintained by translating deductive rules into CLIPS production rules. Users can choose between an OPS5/CLIPS-like or a RuleML-like syntax. R-DEVICE is based on a OO RDF data model, different than the established graph model, which maps resources to objects and encapsulates properties inside resource objects, as traditional OO attributes. In this way, less joins are required to access the properties of a single resource resulting in better inferencing/querying performance. The descriptive semantics of RDF may call for dynamic re-definitions of resource classes and objects, which are handled by R-DEVICE effectively.

This paper describes an object-oriented database language being implemented at Brown for use on workstations, and demonstrates its use in defining an object-oriented programming environment. The database language is illustrated by specifications of the UNIX file system, Ada packages, program structure, and multiple views of program modules. Each example illustrates a different feature of object-oriented programming methodology. Collectively the examples serve both as an introduction to our database language and as a tutorial for object-oriented system programming.

The aim here is to describe how to complete the constructive logicist program, in the author’s book Anti-Realism and Logic, of deriving all the Peano–Dedekind postulates for arithmetic within a theory of natural numbers that also accounts for their applicability in counting finite collections of objects. The axioms still to be derived are those for addition and multiplication. Frege did not derive them in a fully explicit, conceptually illuminating way. Nor has any neo-Fregean done so. These outstanding axioms need to be derived in a way fully in keeping with the spirit and the letter of Frege’s logicism and his doctrine of definition. To that end this study develops a logic, in the Gentzen-Prawitz style of natural deduction, for the operation of orderly pairing. The logic is an extension of free first-order logic with identity. Orderly pairing is treated as a primitive. No notion of set is presupposed, nor any set-theoretic notion of membership. The formation of ordered pairs, and the two projection operations yielding their left and right coordinates, form a coeval family of logical notions. The challenge is to furnish them with introduction and elimination rules that capture their exact meanings, and no more. Orderly pairing as a logical primitive is then used in order to introduce addition and multiplication in a conceptually satisfying way within a constructive logicist theory of the natural numbers. Because of its reliance, throughout, on sense-constituting rules of natural deduction, the completed account can be described as ‘natural logicism’.

We propose a general framework to study BRST-related transformations. We investigate different forms of BRST and BRST-related symmetries, realized within a prototypical first-class system, including ordinary BRST, anti-BRST, dual-BRST, anti-dual-BRST and additional sets of new BRST-related symmetries. We identify a precise discrete group of symmetries of the ghost sector, responsible for connecting the various forms of BRST-related transformations. Their distinct roles in different Hamiltonian and Lagrangian approaches are clarified. As a unifying framework, we use a gauge invariant prototypical first-class system encompassing an extensive class of physical models.

We present a novel approach to generate functional vectors based on assertions for RTL design verification. Our approach combines program-slicing based design extraction, word-level SAT and dynamic searching techniques. Through design extraction, vectors generation need only concern about the design parts related to the given assertion, thus large practical designs can be handled. Constraints Logic Programming (CLP) naturally models mixed bit-level and word-level constraints, and word-level SAT techniques solve the mixed constraints in a unified framework, which gain perfect performance. Initial states derived from dynamic simulation can dramatically accelerate the searching process of functional vectors generation. A prototype system has been built, and the experimental results on some public benchmarks and industrial circuits demonstrate the efficiency of our approach and its applicability to large practical designs.

In this paper we propose a set‐oriented rule‐based method definition language for object‐oriented databases. Most existing object‐oriented database systems exploit a general‐purpose imperative object‐oriented programming language as the method definition language. Because methods are written in a general‐purpose imperative language, it is difficult to analyze their properties and to optimize them. Optimization is important when dealing with a large amount of objects as in databases. We therefore believe that the use of anad hoc, set‐oriented language can offer some advantages, at least at the specification level. In particular, such a language can offer an appropriate framework to reason about method properties.In this paper, besides defining a set‐oriented rule‐based language for method definition, we formally define its semantics, addressing the problems of inconsistency and non‐determinism in set‐oriented updates. Moreover, we characterize some relevant properties of methods, such as conflicts among method specifications in sibling classes and behavioral refinement in subclasses. Copyright © 2003 John Wiley & Sons, Ltd.

We show how the dynamics of database systems can be modeled by making states first-class citizens in an object-oriented deductive database language. With states at the same time acting as objects, methods, or classes, several concepts of dynamic entities can be implemented, allowing an intuitive, declarative modeling of the application domain. Exploiting the natural stratification induced by the state sequence, the approach also provides an implementable operational semantics.The method is applicable to arbitrary object-oriented deductive database languages which provide a sufficiently flexible syntax and semantics. Provided an implementation of the underlying database language, any specification in the presented framework is directly executable, thus unifying specification, implementation, and metalanguage for proving properties of a system.The concept is applied to F-Logic. Besides the declarative semantics given by the rules of a State-F-Logic program, the use of F-Logic's inheritance semantics for modeling states provides an effective operational semantics exploiting the naturally given state-stratification. State-F-Logic programs can be executed using the Florid implementation.KeywordsState TermDynamic ObjectDynamic ClassisGround AtomGround InstanceThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

There is a growing need of knowledge description of manufacturing equipment and their capabilities for users, in order to efficiently obtain the on-demand services of manufacturing equipment in cloud manufacturing, and the understanding of the manufacturing capability of equipment is the most important basis for optimizing the cloud service management. During the manufacturing processes, a number of uncertain incidents may occur, which could degrade the manufacturing system performance or even paralyze the production line. Hence, all aspects about the equipment should be reflected within the knowledge description, and the static and dynamic information are both included in the knowledge model of manufacturing equipment. Unification and dynamics are the most important characteristics of the framework of knowledge description. The primary work of this study is fourfold. First, three fundamental ontologies are built, namely, basic information ontology, functional ontology, and manufacturing process ontology. Second, the correlation between the equipment ontology and the fundamental ontology that forms the unified description framework is determined. Third, the mapping relationship between the real-time condition data and the model of manufacturing equipment capability ontology is established. On the basis of the mapping relationship, the knowledge structure of the manufacturing equipment capability ontology is able to update in real-time. Finally, a prototype system is developed to validate the feasibility of the proposed dynamic modeling method. The system implementation demonstrates that the proposed knowledge description framework and method are capable of reflecting the current conditions and the dynamic capability of manufacturing equipment.

In this paper we introduce DOODLE, a new visual and declarative language for object-oriented databases. The main principle behind the language is that it is possible to display and query the database with arbitrary pictures . We allow the user to tailor the display of the data to suit the application at hand or her preferences. We want the user-defined visualizations to be stored in the database, and the language to express all kinds of visual manipulations. For extendibility reasons, the language is object-oriented. The semantics of the language is given by a well-known deductive query language for object-oriented databases. We hope that the formal basis of our language will contribute to the theoretical study of database visualizations and visual query languages, a subject that we believe is of great interest, but largely left unexplored.