While early knowledge-based systems suffered the frequent criticism of having little relevance to the real world, an increasing number of current applications deal with complex, real-world problems. Due to the complex...
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While early knowledge-based systems suffered the frequent criticism of having little relevance to the real world, an increasing number of current applications deal with complex, real-world problems. Due to the complexity of real-world situations, no one general software technique can produce adequate results in different problem domains, and artificial intelligence usually needs to be integrated with conventional paradigms for efficient solutions. The complexity and diversity of real-world applications have also forced the researchers in the AI field to focus more on the integration of diverse knowledge representation and reasoning techniques for solving challenging, real-world problems. Our development environment, BEST (Blackboard-based Expert Systems Toolkit), is aimed to provide the ability to produce large-scale, evolvable, heterogeneous intelligent systems. BEST incorporates the best of multiple programming paradigms in order to avoid restricting users to a single way of expressing either knowledge or data. It combines rule-based programming, object-oriented programming, logic programming, procedural programming and blackboard modelling in a single architecture for knowledge engineering, so that the user can tailor a style of programming to his application, using any or arbitrary combinations of methods to provide a complete solution. The deep integration of all these techniques yields a toolkit more effective even for a specific single application than any technique in isolation or collections of multiple techniques less fully integrated. Within the basic, knowledge-based programming paradigm, BEST offers a multiparadigm language for representing complex knowledge, including incomplete and uncertain knowledge. Its problem solving facilities include truth maintenance, inheritance over arbitrary relations, temporal and hypothetical reasoning, opportunistic control, automatic partitioning and scheduling, and both blackboard and distributed problem-solving paradi
We propose a novel formalism, called Frame Logic (abbr., F-logic), that accounts in a clean and declarative fashion for most of the structural aspects of object-oriented and frame-based languages. These features inclu...
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We propose a novel formalism, called Frame Logic (abbr., F-logic), that accounts in a clean and declarative fashion for most of the structural aspects of object-oriented and frame-based languages. These features include object identity, complex objects, inheritance, polymorphic types, query methods, encapsulation, and others. In a sense, F-logic stands in the same relationship to the object-oriented paradigm as classical predicate calculus stands to relational programming. F-logic has a model-theoretic semantics and a sound and complete resolution-based proof theory. A small number of fundamental concepts that come from object-oriented programming have direct representation in F-logic;other, secondary aspects of this paradigm are easily modeled as well. The paper also discusses semantic issues pertaining to programming with a deductive object-oriented language based on a subset of F-logic.
Inheritance, together with object and class, is the key concept of objectoriented systems. Adopting the concept-oriented view (COV for short) of inheritance, current OO systems such as GemStone, Orion, C++, O-2, Post...
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Inheritance, together with object and class, is the key concept of objectoriented systems. Adopting the concept-oriented view (COV for short) of inheritance, current OO systems such as GemStone, Orion, C++, O-2, PostGres, Iris, and SmallTalk dominantly interpret inheritance by retaining all attributes and methods in a subclass from its superclass, and by supporting the specification of additional attributes and methods in the subclass. However, this monotonic extension property may result in a redundant subclass representation which in turn gives rise to update anomalies. Thus extra effort in practice used to prevent these problems from happening is to change an IS-A relationship in COV of hierarchy into sibling in the program-oriented view (POV for short) hierarchy. However, the dichotomy between the concept and implementation leads to a significant difference of the class hierarchy between the designing phase and implementation phase of OO systems, hence increases the complexity in designing OO systems. In this paper, rye show that, when the subclass attributes are linearly related to the superclass attributes (the attributes in the superclass can be linearly expressed by those in the subclass), linear subclass assertions/constraints can be elegantly used to resolve the problems such as the redundant subclass representation, and update anomalies. We have proved that (1) given a linear subclass assertion, a non-redundant subclass representation can be automatically decided, and the bilateral mappings between the class and the determined subclass can be automatically constructed, and (2) given a user-chosen subclass representation and the mapping from the chosen subclass to the superclass, the linear subclass assertion and inverse mapping can be automatically constructed, and (3) placing an object into the most specific class in an ISA class hierarchy can be automatically conducted. The proposed novel ideas have been prototyped on GemStone/Smalltalk on a SunSparc/U
This paper presents a framework called logical knowledge object (LKO),which is taken as a basis of the dependable development of knowledge based systems(KBSs). LKO combines logic programming and object-oriented progra...
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This paper presents a framework called logical knowledge object (LKO),which is taken as a basis of the dependable development of knowledge based systems(KBSs). LKO combines logic programming and object-oriented programming paradigms, where objects are viewed as abstractions with states,constraints, behaviors and inheritance. The operational semantics defined in the style of natural semantics is simple and clear. A hybrid knowledge represen-tation amalgamating rule, frame, semantic network and blackboard is available for both most structured and flat knowledge. The management of knowledge bases has been formally specified. Accordingly, LKO is well suited for the formal representation of knowledge and requirements of KBSs. Based on the framework, verification techniques are also explored to enhance the analysis of requirement specifications and the validation of KBSs. In addition, LKO pro-vides a methodology for the development of KBSs, applying the concepts of rapid prototyping and top-down design to deal with changing and incomplete requirements, and to provide multiple abstract models of the domain, where formal methods might be used at each abstract level.
In order to support environmental scientists in finding an ''adequate'' model for the system they are investigating, a computer program is necessary that allows its users to perform simulations for dif...
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In order to support environmental scientists in finding an ''adequate'' model for the system they are investigating, a computer program is necessary that allows its users to perform simulations for different models, to assess the identifiability and to estimate the values of model parameters (using measured data), and to estimate prediction uncertainty. These requirements, especially that of providing much freedom in model formulation, are difficult to realize in such a program. In this paper, it is shown how object-oriented program design techniques were employed to facilitate the realization of an identification and simulation program for aquatic systems (AQUASIM) that is very flexible with regard to model formulation and that provides methods of sensitivity analysis, parameter estimation and uncertainty analysis in addition to simulation. It is the goal of this paper to encourage developers of environmental software to revise previously used program structures and to employ modern program design techniques.
Today, advances in personal computing are helping corporations compete in a dynamic, global economy. Businesses, however, need new ways to deliver information systems in a faster, more cost-effective manner. object te...
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Today, advances in personal computing are helping corporations compete in a dynamic, global economy. Businesses, however, need new ways to deliver information systems in a faster, more cost-effective manner. object technology, in the form of COM will help businesses meet these needs. This article presents GDES for client/server computing based on OLE and objectBroker. GDES is a huge step forward in UBS's client/server computing strategy. It serves as a blueprint for future UBS applications where information is stored on a variety of dissimilar computers and databases.
The development of an innovative clinical decision-support project such as the University of Minnesota's Clinical Workstation initiative mandates the use of modern client-server network architectures. Preexisting ...
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The development of an innovative clinical decision-support project such as the University of Minnesota's Clinical Workstation initiative mandates the use of modern client-server network architectures. Preexisting conventional laboratory information systems (LIS) cannot be quickly replaced with client-server equivalents because of the cost and relative unavailability of such systems. Thus, embedding strategies that effectively integrate legacy information systems are needed. Our strategy led to the adoption of a multi-layered connection architecture that provides a data feed from our existing LIS to a new network-based relational database management system. By careful design, we maximize the use of open standards in our layered connection structure to provide data, requisition, or event messaging in several formats. Each layer is optimized to provide needed services to existing hospital clients and is well positioned to support future hospital network clients.
In many firms 50% and more of software development capacities are absorbed by maintenance tasks. To solve the maintenance problems associated with old programs methods and tools of software renovation have been develo...
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In many firms 50% and more of software development capacities are absorbed by maintenance tasks. To solve the maintenance problems associated with old programs methods and tools of software renovation have been developed. Beginning with a description of the maintenance problem we depict the components of program renovation (restructuring, reverse engineering, reengineering) and explore the possibilities of tool support. Because methods of object-orientation promise a distinct reduction of maintenance costs in the area of software newdevelopment we propose program renovation with transition in an object-oriented architecture in the framework of an object-oriented reengineering.
This paper describes the use of an object-oriented application framework to implement a PC-based tool kit for use by EMS software support personnel in software maintenance activities including training, documentation ...
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ISBN:
(纸本)0780326644
This paper describes the use of an object-oriented application framework to implement a PC-based tool kit for use by EMS software support personnel in software maintenance activities including training, documentation development, and trouble-analysis. In addition to a description of the development of the underlying code which provides the tool kit functionality, the paper describes the steps necessary to instantiate the tool kit on a given EMS subsystem.
This paper presents a visual language for integrated circuit (IC) test. It abstracts the test flow as several classes which map to some forms. Test engineers can use the form-based environment which reduces the cost o...
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ISBN:
(纸本)0819420123
This paper presents a visual language for integrated circuit (IC) test. It abstracts the test flow as several classes which map to some forms. Test engineers can use the form-based environment which reduces the cost of developing high quality programs. Test classes are defined by AT&T C++ 2.0. Forms are implemented by X-Window. All the systems run on a SUN SPARC workstation.
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