Object-oriented Formalism Research Articles

Deriving Dependently-Typed OOP from First Principles

The expression problem describes how most types can easily be extended with new ways to produce the type or new ways to consume the type, but not both. When abstract syntax trees are defined as an algebraic data type, for example, they can easily be extended with new consumers, such as print or eval , but adding a new constructor requires the modification of all existing pattern matches. The expression problem is one way to elucidate the difference between functional or data-oriented programs (easily extendable by new consumers) and object-oriented programs (easily extendable by new producers). This difference between programs which are extensible by new producers or new consumers also exists for dependently typed programming, but with one core difference: Dependently-typed programming almost exclusively follows the functional programming model and not the object-oriented model, which leaves an interesting space in the programming language landscape unexplored. In this paper, we explore the field of dependently-typed object-oriented programming by deriving it from first principles using the principle of duality. That is, we do not extend an existing object-oriented formalism with dependent types in an ad-hoc fashion, but instead start from a familiar data-oriented language and derive its dual fragment by the systematic use of defunctionalization and refunctionalization. Our central contribution is a dependently typed calculus which contains two dual language fragments. We provide type- and semantics-preserving transformations between these two language fragments: defunctionalization and refunctionalization. We have implemented this language and these transformations and use this implementation to explain the various ways in which constructions in dependently typed programming can be explained as special instances of the general phenomenon of duality.

Application of BIM technology in operation of port marine structures

The features of the BIM model development for marine port facilities operation are discussed. Infrastructure objects differ significantly from linear and area objects, the use of information modeling for transport infrastructure requires a new approach to organization of design, construction and especially for operation. Most seaports were built long ago and there is not to have the project documentation for them. It is therefore very relevant is the problem of adapting existing building and design documentation to develop models of operation. Infrastructure projects always have a large number of interconnections that are irregular and difficult to formalize into an information model. Port berthing facilities in an intensive mode interact with the courts, a water space, the cargo base and special cargo handling equipment. On the example of the design model of the seaport, we collected sufficient data for their further integration into the BIM model and the transfer of information in digital form for its repeated use at different stages of the life cycle of the seaport. The individual information schemes and elements for standardization of the design of offshore mooring structures, taking into account of turnover in object-oriented format with attribute data are offered. The model includes the necessary information on all parameters of operation of the berthing facility, planning of measures for emergency situations, standard calendar work plan, schedules for monitoring the technical condition, financial estimates for operational maintenance, repairs, etc. The activities on the automation of deformation monitoring system, calculation of structural strength of the main structural elements and control risks are additionally proposed. The transition to life-cycle contracts in the operation of marine berthing facilities is justified.

Reengineering Object-Oriented Fuzzy Spatiotemporal Data into XML

With the rapid development of the Internet, XML has become the defacto standard for integrating and exchanging data. Since more and more business data are stored in object-oriented database, we study the methodology of modeling fuzzy spatiotemporal data and transforming fuzzy spatiotemporal data from object-oriented databases to XML as well. In order to allow for better and platform independent sharing of fuzzy spatiotemporal data stored in an object-oriented format, we devise a fuzzy spatiotemporal data model in object-oriented database to capture the semantics of spatiotemporal features. In particular, XML schema best describes the existing fuzzy object-oriented schema, and we investigate the transforming rules of spatiotemporal data from fuzzy object-oriented database to XML. Furthermore, an instance demonstrates the validation of our approach. Such approach of transformation can provide a significant consolidation of the interoperability of fuzzy spatiotemporal data from object-oriented databases to XML.

Content Repository in Object Oriented data model

The need for creating content repository stores for e-learning systems grows as the number of available materials increases. Moreover, along with the number of courses, the problem of describing them in a unified form appears. While there are standards used for strict classification of elearning content, the store model still seems to be based on preservative relational databases approach.In this paper we introduce an idea to represent the e-learning content management information in the well organized object-oriented form based on a prospective object-oriented database.

Formal transformation from fuzzy object-oriented databases to fuzzy XML

XML has become the standard for publishing and exchanging data on the Web. Since most of the business data nowadays are stored in structured databases including relational and object-oriented databases (OODB), it is of significance to automate the transformation process and generate the XML data containing information from existing databases. At the same time, information imprecision and uncertainty exist in many practical applications, and for this reason, fuzzy data modeling has been extensively investigated in various data models. As such, there is an increasing need to effectively publish fuzzy structured data as fuzzy XML documents for Web-based applications. In this paper, we take a significant step in a fundamental consolidation of fuzzy XML. In particular, we are interested in finding an XML schema that best describes the existing fuzzy object-oriented schema. To accomplish this, we first offer mapping formalisms to capture the semantics of fuzzy XML Schema and fuzzy object-oriented schema. To allow for better and platform independent sharing of data stored in an object-oriented format, we investigate the formal transformation from fuzzy OODB to fuzzy XML and develop a set of rules to assist in the transformation process.

Efficient large-scale configuration via integer linear programming

AbstractConfiguration of large-scale applications in an engineering context requires a modeling environment that allows the design engineer to draft the configuration problem in a natural way and efficient methods that can process the modeled setting and scale with the number of components. Existing configuration methods in artificial intelligence typically perform quite well in certain subareas but are hard to use for general-purpose modeling without mathematical or logics background (the so-called knowledge acquisition bottleneck) and/or have scalability issues. As a remedy to this important issue both in theory and in practical applications, we use a standard modeling environment like the Unified Modeling Language that has been proposed by the configuration community as a suitable object-oriented formalism for configuration problems. We provide a translation of key concepts of class diagrams to inequalities and identify relevant configuration aspects and show how they are treated as an integer linear program. Solving an integer linear program can be done efficiently, and integer linear programming scales well to large configurations consisting of several thousands components and interactions. We conduct an empirical study in the context of package management for operating systems and for the Linux kernel configuration. We evaluate our methodology by a benchmark and obtain convincing results in support for using integer linear programming for configuration applications of realistic size and complexity.

Content Repository in Object Oriented data model

The need for creating content repository stores for e-learning systems grows as the number of available materials increases. Moreover, along with the number of courses, the problem of describing them in a unified form appears. While there are standards used for strict classification of elearning content, the store model still seems to be based on preservative relational databases approach.In this paper we introduce an idea to represent the e-learning content management information in the well organized object-oriented form based on a prospective object-oriented database.

Entity-relationship and object-oriented formalisms for modeling spatial environmental data

Entity-Relationship (ER) and Object-Oriented (OO) formalisms are often used to model environmental information of databases or computer programs. The majority of the environmental information is georeferenced. However, for 20 years, researchers have proposed different methods to adapt ER and OO to model spatial data. Spatial information is complex, and the goal is to simplify its representation in conceptual models. The goal of this paper is to propose a classification and a list of work in the area of ER and OO formalisms for spatial information. Numerous bibliographical references on the subject are also provided. The article targets mainly researchers working in the area of environment domain hoping to find a bibliographical entry to the subject. We present here a synthesis of the principal advances in the field.

Maude Object-Oriented Action Tool

Object-Oriented Action Semantics (OOAS) incorporates object-oriented concepts to the Action Semantics formalism. Its main goal is to obtain more readable and reusable semantics specifications. Moreover, it supports syntax-independent specifications, due to the way classes are written. Maude Object-Oriented Action Tool (MOOAT) is an executable environment for Object-Oriented Action Semantics implemented as a conservative extension of Full Maude and Maude MSOS Tool (MMT). The Modular SOS of Action Notation has been implemented using MMT transitions and Full Maude has been used to implement the Classes Notation. The syntax created by MOOAT is fairly similar to the original Object-Oriented Action Semantics syntax. In addition to it, the tool combines the modularity aspects observed in the object-oriented approach with the efficient execution and analysis of the Maude system. We use MOOAT to describe syntax-independent specifications of programming languages. In this way, we show how Constructive Object-Oriented Action Semantics (COOAS) may be achieved as a combination between Object-Oriented Action Semantics and Constructive Action Semantics (CAS) using MOOAT, in order to increase the modularity aspects observed in the object-oriented formalism. This paper reports on the development of Maude Object-Oriented Action Tool and its application to the formal specification of programming languages.

Product modeling framework for behavioral performance evaluation at design stage

In this paper we present a framework for product behavioral performances evaluation during design process. It is based on the product behavioral modeling approach and uses an evaluation method that determines performance indicators for different domains of the product lifecycle. We are mainly focused on semantic and fuzzy domains that are complex to formalize. We show how the product design solutions represented in a CAD system can be analyzed to evaluate the product performances at some specific domains. After a short state of art on product modeling methods we define a FBS product behavioral modeling approach based on the object-oriented modeling formalism. Here the product is described as a conceptual object with properties and formal criteria evaluation methods for different domains. Then a behavioral performance evaluation procedure is detailed and we outline software architecture for implementation in a CAD system. An application for product maintainability assessment of an industrial trailer illustrates the approach.

Machine capability and fixturing constraints-imposed automatic machining set-ups generation

An aspect of process planning that has not received a good deal of attention is set-up planning. Machine tool configuration and fixture constrain operations in process planning. The paper presents a set-up planning module as part of a feature-based process planning system with an access of a manufacturing database. Data on component geometry, dimensions and tolerances are used to extract constraint-imposed precedence relations between features. The geometric relationship between the fixture and the machine tool is represented in an object-oriented format. Taking machine capabilities and fixturing strategies into account, the set-up planning module automatically generates multiple machining set-ups via a procedure. A case study is given to demonstrate how the procedure works. The presented module helps facilitate automation of set-up planning implementations for machining of near net shape prismatic parts on shop floor.

An Object-oriented Interpretation of the EAT System

In a previous paper we characterized, in the Category Theory setting, a class of implementations of Abstract Data Types, which has been suggested by the way of programming in the EAT system. (EAT, Effective Algebraic Topology, is one of Sergeraert’s systems for effective homology and homotopy computation.) This characterization was established using classical tools, in an unrelated way to the current mainstream topics in the field of Algebraic Specifications. Looking for a connection with these topics, we have found, rather unexpectedly, that our approach is related to some object-oriented formalisms, namely hidden specifications and the coalgebraic view. In this paper, we explore these relations making explicit the implicit object-oriented features of the EAT system and generalizing the data structure analysis we had previously done.

An Object-Oriented Formalism for Feature-Based Distributed Concurrent Engineering

The use of feature-based design and Concurrent Engineering promises substantial benefits but their successful implementation is hampered by the lack of a suitable formalism, particularly where, as is often the case, participants are geographically separated. This overall research area can be termed feature-based distributed Concurrent Engineering (FBDCE). The work presented in this paper is focused on how to represent FBDCE in a situation where the participants may be geographically separated, and how to implement it in a formal and systematic way. A representation formalism is proposed for that purpose. This paper first overviews the FBDCE process and identifies the knowledge gaps in existing FBDCE support. A formalism for remote FBDCE is then presented. This formalism uses an object-oriented approach, called Design with Objects (DwO), where features are represented as lower level objects. An Internet network-based implementation of this formalism is described that uses the Internet to support FBDCE. An example is used to illustrate the implementation. The use of DwO for FBDCE offers several important advantages in computability, in that a design process model obtained using DwO is a computable model, in reusability, in that once a design object in DwO has been established, it can be used repeatedly, and in exchangeability, in that objects can be readily exchanged with other objects with similar interfaces. The main contributions of this paper are threefold. First, an object-oriented approach, DwO, to feature based design is described. Second, a formalism for FBDCE using DwO is presented. Third, the use of this formalism is illustrated with an Internet-based implementation showing how the formalism can be used for a specific problem.

OODS: an object-oriented design system — an example of electronics assemblies

Object-oriented design is viewed as a promising approach for handling a wide variety of design problems. However, little work has been done to date on developing object-oriented design systems that can handle a variety of design problems. This paper describes an object-oriented design system (OODS) that uses an object-oriented formalism called design with objects (DwO). The background to DwO is described including the DwO design model, the other design objects in DwO, the use of DwO methods and the resulting design process models. The decomposition of objects in OODS is then described, followed by a description of the configuration system object and the user interface (UI) object. The implementation of OODS is then detailed. This implementation uses the Internet to communicate between OODS and users, and with databases that may be geographically scattered. The use of OODS is illustrated by a description of an application as an example that involves the design of electronics assemblies. The contribution of this paper is threefold. First, a new object-oriented design formalism is presented. Second, an implementation architecture for this formalism is described, and, third, an example application is presented showing how this approach can be used.

LIFE-CYCLE MANAGEMENT OF INFORMATION AND DECISIONS FOR SYSTEM ANALYSES

Quality products require quality analysis; analysis that delivers the necessary behavioural information using the assigned resources in the prescribed time frame. Using analysis tools effectively requires deep understanding of theory and practice. Practical analysis could be supported by managing analysis tools information and their past uses. If managed properly, this information would be beneficial for present and future tool reuse. Following an examination of analysis activities, a model of analysis activities is developed including various aspects that influence it. The model includes all contextual information of analysis. With this information the model could improve analysis as well as prevent serious analysis errors. The model called AML—analysis modelling language—is described precisely with the object-oriented formalism unified modelling language (UML). The most important part of AML, the static structure diagram, is discussed in this paper. AML could be transformed with reasonable effort into an analysis process management system.

The whole-part relationship in object modelling: a definition in cOlOr

In object models built according to popular object-oriented formalisms, the commonest relationship types (excluding inheritance) are the structural relationships of association and of whole-part (often called aggregation). This last type is well known to have no accurately prescribed semantics. Here, some of the aggregation semantics frequently presented in the literature and sometimes supported in current object-oriented modelling languages, especially UML, are analysed and criticised. Because of defects, the use of a modelling notation based on these aggregation semantics is dubious and limited. Moreover, many properties are candidates for characterising the whole-part relationship provided that no redundancy and no inconsistency exist between them. A framework known as cOlOr is then offered by means of a metamodel in which the Whole-Part metatype inherits from the Structural-Relationship metatype. Defining a specific aggregation semantics leads then, first, within cOlOr, to the creation of a subtype of the Whole-Part metatype. Next, the behaviour of this last type is extended and/or restricted in using a constraint-based approach. Such a process is developed particularly for considering Composition in UML and Aggregation in OML more formally, as well as for dealing with domain-dependent aggregation semantics. Since a non-negligible feature of cOlOr is the availability of a C++ library that implements the proposed metamodel, some implementation concerns are also briefly discussed.

Open architecture modelling and simulation in process hazard assessment

Dynamic modelling and simulation of a chemical process in emergency conditions is considered. Such modelling and simulation often requires rapid implementation of model changes by the process engineer followed by simulation runs. A simulator with an open architecture structure is presented where the model components (equations) are stored in an object-oriented form in a database, enabling rapid and easy modification of the model. A general-purpose numerical solver is used for solving the model and plotting the pertinent results. An example is presented, where the use of the proposed simulator enables a rapid identification of the right strategy to prevent development of runaway temperature conditions in a reactor.

Integrated model management in the data warehouse era

Integrated modeling environments have historically been viewed as extensions of database management systems. Now that the WorldWideWeb has commandeered the computing landscape, a distributed perspective is required for model management. Our approach to distributed integrated modeling combines a data warehouse of decision metrics, a model warehouse of decision model structural representations, a conversion process to represent models in object-oriented form using the unified modeling language (UML), and component-based software plug-ins which augment typical cross-tabulations analysis with more sophisticated solvers from optimization, statistics, and other modeling paradigms.

Finite Element Analysis using Component Decomposition and Knowledge-Based Control

This paper presents ongoing research into using Artificial Intelligence (AI) techniques to intelligently control finite element thermal analyses. These techniques are used to implement component level decomposition of the physical domain, and to integrate domain information into the analysis process to increase computational efficiency. We have implemented these techniques into a new proof-of-concept finite element program which employs a blackboard architecture to integrate the various numerical and symbolic knowledge sources. The blackboard architecture also supports the storage (and retrieval) of data in an object-oriented form. A test problem involving transient thermal analysis of an integrated circuit package is presented. Use of the proposed method showed a significant decrease in the number of floating point operations required compared to conventional solution technologies. The penalty associated with this saving was approximately a 4% difference in the calculated temperature in the critical region of interest.

An object-oriented formalism for electronics assemblies components selection

An electronics assembly (EA) is a backbone of electronic or electromechanical products, where its functions are implemented by combining components and their interconnections (conductors) on a substrate plate. The design of EAS is relatively complex and encompasses the consideration of many diverse considerations. This paper is concerned with the central area of electronic assemblies component selection (EACS), and with considering constraints at this stage to avoid multiple repetitions of the design process. The use of such EACS promises substantial benefits but its successful implementation is hampered by the lack of a suitable formalism, particularly where, as is often the case, participants are geographically separated. The work presented in this paper is focused on how to represent EACS, where the participants may be remote, and how to implement it in a formal and systematic way. A representation formalism is proposed for that puspose.