Extending the UML concepts to transform natural language queries with fuzzy semantics into SQL

Database applications tend toward getting more versatile and broader to comply with the expansion of various organizations. However, naïve users usually suffer from accessing data arbitrarily by using formal query languages. Therefore, we believe that accessing databases using natural language constructs will become a popular interface in the future. The concept of object-oriented modeling makes the real world to be well represented or expressed in some kinds of logical form. Since the class diagram in UML is used to model the static relationships of databases, in this paper, we intend to study how to extend the UML class diagram representations to capture natural language queries with fuzzy semantics. By referring to the conceptual schema throughout the class diagram representation, we propose a methodology to map natural language constructs into the corresponding class diagram and employ Structured Object Model (SOM) methodology to transform the natural language queries into SQL statements for query executions. Moreover, our approach can handle queries containing vague terms specified in fuzzy modifiers, like ‘good’ or ‘bad’. By our approach, users obtain not only the query answers but also the corresponding degree of vagueness, which can be regarded as the same way we are thinking.     

Detection of user-defined,semantically high-level,composite events,and retrieval of event queries

Detecting events of interest from video sequences, and searching and retrieving events from video databases are important and challenging problems. Event of interest is a very general term, since events of interest can vary significantly among different applications and users. A system that can only detect and/or retrieve a finite set of predefined events will find limited use. Thus, the event detection and retrieval problems introduce additional challenges including providing the user with flexibility to specify customized events with varying complexity, and communicating user-defined events to a system in a generic way. This paper presents a spatio-temporal event detection system that lets users specify semantically high-level and composite events, and then detects their occurrences automatically. Events can be defined on a single camera view or across multiple camera views. In addition to extracting information from videos, detecting customized events, and generating real-time alerts, the proposed system uses the extracted information in the search, retrieval, data management and investigation context. Generated event meta-data is mapped into tables in a relational database against which queries may be launched. It is therefore possible to retrieve events based on various attributes. Moreover, a variety of statistics can be computed on the event data. Thus, the presented system provides capabilities of a fully integrated smart system.     

Rule-based and object-based event structures for membrane systems

We introduce two event structures for basic membrane systems with one membrane. In the rule-based structure an event is given by a single rule application, while in the object-based structure an event is given by the occurrence of a type of resource (in a certain quantity). Both event structures are introduced without the use of fresh names to distinguish between similar events. We discuss causality by using the order relation on the object-based event structure as well as a dependence relation on the rules of the membrane system.     

CUDL language semantics: Updating FDB data

The semantics for data manipulation of the database language CUDL - Conceptual Universal Database Language - designed to manage dynamic database environments, are presented. This language conforms to the FDB (Frame DataBase) data model, offering a simple, easy and efficient platform for the use of the FDB model. Otherwise the management and operation of FDB data is laborious and time-consuming and it requires from the user a very good acquaintance of the proposed model, the structures and organisation of it as well as the processes of the management of elements that compose it. In this paper we present in depth the semantics of the way of handling the data, in order to search and transform information, in an FDB data source. We present the analysis of simple and complex cases that led us to synthesize valid and simple semantic rules that determine the data manipulation operations. The more sophisticated and demanding constructs, used in the language, for query specification, query processing and object manipulation are discussed and evaluated.     

The connection between an event structure semantics and an operational semantics forTCSP

The relation between an operational interleaving semantics forTSCP based on a transition system and a compositional true concurrency semantics based on event structures is studied. In particular we extend the consistency result of Goltz and Loogan [15] forTCSP processes without recursion to the general case. Thus we obtain for everyTCSP processP that its operational meaningO(P) and the interleaving behaviourO( M3P3) which is derived from the event structureM3P3 associated withP are bisimilar.     

The red and black semantics: a fuzzy language

The complexity of abstract art languages create new semantics in art. This model tries to implement its conceptual language within creating a new virtual environment. The gap between art and technology has been approached with a fuzzy logic engine which uses a red and black semantic codification. The examples include the application of this metalanguage to a virtual artwork experimentation.     

A metalogic programming approach: language,semantics and applications

Abstract

This paper presents a logic programming language of novel conception, called Reflective Prolog, which allows declarative metaknowledge representation and metareasoning. The language is defined by augmenting pure Prolog (Horn clauses) with capabilities of self-reference and logical reflection. Self-reference is designed as a quotation device (a carefully defined naming relation) which allows the construction of metalevel terms that refer to object-level terms and atoms. Logical reflection is designed as an unquotation mechanism (a distinguished truth predicate) which relates names to what is named, thus extending the meaning of domain predicates. The reflection mechanism is embodied in an extended resolution procedure which automatically switches the context between levels. This implicit reflection relieves the programmer from having to explicitly deal with control aspects of the inference process. The declarative semantics of a Reflective Prolog definite program P is provided in terms of the least reflective Herbrand model of P, characterized by means of a suitable mapping defined over the Herbrand interpretations of P. The extended resolution is proved sound and complete with respect to the least reflective Herbrand model. By illustrating Reflective Prolog solutions to an organic set of problems, and by discussing the main differences with respect to other approaches to logic metaprogramming, we show that the proposed language deploys, within its field of action, greater expressive and inferential power than those available till now. The interpreter of the language has been fully implemented. Because of its enhanced power, logic semantics and working interpreter, Reflective Prolog is offered as a contribution toward making the declarative approach of logic programming applicable to the development of increasingly sophisticated knowledge-based systems.     

Linking operational semantics and algebraic semantics for a probabilistic timed shared-variable language

Complex software systems typically involve features like time, concurrency and probability, with probabilistic computations playing an increasing role. However, it is currently challenging to formalize languages incorporating all those features. Recently, the language PTSC has been proposed to integrate probability and time with shared-variable concurrency (Zhu et al. (2006, 2009) [51] and [53]), where the operational semantics has been explored and a set of algebraic laws has been investigated via bisimulation. This paper investigates the link between the operational and algebraic semantics of PTSC, highlighting both its theoretical and practical aspects.The link is obtained by deriving the operational semantics from the algebraic semantics, an approach that may be understood as establishing soundness of the operational semantics with respect to the algebraic semantics. Algebraic laws are provided that suffice to convert any PTSC program into a form consisting of a guarded choice or an internal choice between programs, which are initially deterministic. That form corresponds to a simple execution of the program, so it is used as a basis for an operational semantics. In that way, the operational semantics is derived from the algebraic semantics, with transition rules resulting from the derivation strategy. In fact the derived transition rules and the derivation strategy are shown to be equivalent, which may be understood as establishing completeness of the operational semantics with respect to the algebraic semantics.That theoretical approach to the link is complemented by a practical one, which animates the link using Prolog. The link between the two semantics proceeds via head normal form. Firstly, the generation of head normal form is explored, in particular animating the expansion laws for probabilistic interleaving. Then the derivation of the operational semantics is animated using a strategy that exploits head normal form. The operational semantics is also animated. These animations, which again supports to claim soundness and completeness of the operational semantics with respect to the algebraic, are interesting because they provide a practical demonstration of the theoretical results.     

Moving GeoPQL: a pictorial language towards spatio-temporal queries

Nowadays, two of the main challenges involving spatio-temporal databases concern the integration of their spatial and temporal features to store and query spatial objects changing over time, and the development of a simple and friendly language to query spatio-temporal data. In this paper we gather these two challenges by proposing Moving GeoPQL, a language defined in order to express spatio-temporal queries, extending the Geographical Pictorial Query language (GeoPQL). The proposed evolution is based on the concept of temporal layer that allows specifying the spatial configuration of moving objects in a time interval. More layers allow representing changes in terms of spatial configurations. Some examples of query formulation and system operation are described in the article. Finally, an experiment has been carried out for evaluating the usability of the Moving GeoPQL system. Results of this experiment showed that it facilitates the spatio-temporal query formulation since it is more user-friendly and ease to use compared to textual query languages.     

An axiomatic semantics for the synchronous language Gentzen

We propose an axiomatic semantics for the synchronous language Gentzen, which is an instantiation of the paradigm Timed Concurrent Constraint Programming proposed by Saraswat, Jagadeesan and Gupta. We view Gentzen as a prototype of the class of state-oriented synchronous languages, since it offers the basic constructs that are shared by the languages in the class. Since synchronous concurrency cannot be simulated by arbitrary interleaving, we cannot exploit “head normal forms”, on which axiomatic theories for asynchronous process calculi are based. We suggest how axiomatic semantics for other state-oriented synchronous languages can be obtained by expressing constructs of such languages in terms of Gentzen constructs.     

Nivel: a metamodelling language with a formal semantics

Much work has been done to clarify the notion of metamodelling and new ideas, such as strict metamodelling, distinction between ontological and linguistic instantiation, unified modelling elements and deep instantiation, have been introduced. However, many of these ideas have not yet been fully developed and integrated into modelling languages with (concrete) syntax, rigorous semantics and tool support. Consequently, applying these ideas in practice and reasoning about their meaning is difficult, if not impossible. In this paper, we strive to add semantic rigour and conceptual clarity to metamodelling through the introduction of Nivel, a novel metamodelling language capable of expressing models spanning an arbitrary number of levels. Nivel is based on a core set of conceptual modelling concepts: class, generalisation, instantiation, attribute, value and association. Nivel adheres to a form of strict metamodelling and supports deep instantiation of classes, associations and attributes. A formal semantics is given for Nivel by translation to weight constraint rule language (WCRL), which enables decidable, automated reasoning about Nivel. The modelling facilities of Nivel and the utility of the formalisation are demonstrated in a case study on feature modelling.

A set‐oriented method definition language for object databases and its semantics

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 an ad 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.     

Enhanced event structures: Towards a true concurrency semantics for E-LOTOS

E-LOTOS is a standard process-algebraic language for formal specification of real-time concurrent and reactive systems. Its originally defined semantics is based on interleaving of events. In the present paper, we propose an enhanced kind of event structures and show how to employ them to give E-LOTOS processes a branching-time true concurrency semantics. The proposed event structures can model real-time processes with data handling and excel in concise representation of event renaming and synchronization.     

A visual language for modeling and executing traceability queries

Current software and systems engineering tools provide only basic trace features, and as a result users are often compelled to construct non-trivial traceability queries using generic query languages such as SQL. In this paper, we present an alternative approach which defines traceability strategies for a project using UML class diagrams and then constructs trace queries as constraints upon subsets of the model. The visual trace modeling language (VTML) allows users to model a broad range of trace queries while hiding underlying technical details and data structures. The viability and expressiveness of VTML for use in a real project are demonstrated through modeling a broadly representative set of queries for a web-based health-care system. It is then evaluated through an experiment with human users to assess the readability and writability of VTML queries in comparison to generic SQL queries. We found that users read and constructed traceability queries considerably faster using VTML than using SQL. Furthermore, visually constructed traceability queries were substantially more correct compared to the same queries constructed with SQL.