Three approaches to the constraint-solving problem in knowledge systems are examined: (1) the development of a domain-dependent constraint solver for qualitative simulation, implementing Kuiper's algorithm in logi...
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Three approaches to the constraint-solving problem in knowledge systems are examined: (1) the development of a domain-dependent constraint solver for qualitative simulation, implementing Kuiper's algorithm in logic programming; (2) the building of a general constraint solver by extending Prolog unification into the inequality and real arithmetic domain; and (3) the use of committed choice nondeterministic languages such as Prolog, CP, and GHC for a concurrent constraint language. Knowledge acquisition for medical diagnostics is considered as an example application.< >
A description is given of the Vbase object-oriented database management system (OO-DBMS), which extends the basic paradigm offered by other object-orientedsystems by allowing the creation of storage classes, in the s...
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A description is given of the Vbase object-oriented database management system (OO-DBMS), which extends the basic paradigm offered by other object-orientedsystems by allowing the creation of storage classes, in the same way that other systems allow the creation of abstract classes. Storage classes control object storage, including dereferencing, object faulting, clustering, sharing and persistence. The notion of a storage manager, upon which this facility is based, is introduced, and it is shown how it is used in Vbase. Storage managers are types, which are organized into a hierarchy similar to but orthogonal to the hierarchy of abstract types. The storage-manager-type hierarchy is user-extensible by subtyping, just as the abstract type hierarchy is. The implementation of the storage-manager abstraction relies on generalizations to operation dispatching and reference resolution. Some features of the current implementation of Vbase and some experiences with it are described.< >
The authors describe the resource management strategy for a multi-arm robotic assembly cell under development at the Electrical Engineering Department of the University of Ottawa. Conceived to support an object-orient...
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The authors describe the resource management strategy for a multi-arm robotic assembly cell under development at the Electrical Engineering Department of the University of Ottawa. Conceived to support an object-orientedprogramming language, this assembly cell has a flexible architecture integrating several functional blocks: a task-scheduler, one or more object presentation units, two or more assembly processors, one or more assembly fixtures, and a free-space manager. The architecture and communication aspects are based upon the natural properties of a distributed real-time robotic system. The advantages of such a system are modularity, flexibility, and the ability to exploit the parallelism inherent in complex robot assembly operations. The authors introduce the idea of considering the physical space within which the system operates as a resource that can be managed as an independent entity within the distributed architecture of the robotic system.< >
The paper explores the problem of understanding imperative programs. It points out the role of the procedural nature of knowledge representation as the main reason for difficulties in understanding this type of progra...
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The paper explores the problem of understanding imperative programs. It points out the role of the procedural nature of knowledge representation as the main reason for difficulties in understanding this type of program. The paper suggests a generic process for reasoning about the knowledge embodied in an imperative program as a way to confront this problem. It proceeds with a concrete implementation of the process and a tool that has been constructed accordingly, thus demonstrating its practical usefulness. The goal of this work is to show a possible direction in automating the software development process rather than presenting a definite solution.< >
Although the shared-information model on which inheritance schemes are based is clean and simple, inheritance implementations encountered in today's object-orientedsystems are usually a lot more complex. The auth...
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Although the shared-information model on which inheritance schemes are based is clean and simple, inheritance implementations encountered in today's object-orientedsystems are usually a lot more complex. The author claims that this complexity mainly originates from a desire to express too many different concepts by means of one very tangled inheritance lattice. He argues in favor of simpler inheritance schemes, intelligible and without exceptions, that allow the user to build more complicated information-retrieval architectures explicitly when necessary. This contributes to the simplicity of the language and hence to the comfort of the programmer. Three different object-orientedlanguages are presented that each illustrate an alternative inheritance mechanism that fulfils these requirements.< >
A workstation has been developed using a single semi-custom VLSI chip, which is capable of running a fast Lisp-based language. It has an interpreter-oriented architecture based on the concept that similar logic functi...
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A workstation has been developed using a single semi-custom VLSI chip, which is capable of running a fast Lisp-based language. It has an interpreter-oriented architecture based on the concept that similar logic functions, essential to list processing, can be realized by multiple implementation of a single logic circuit leading to a simplified datapath structure. The workstation exhibits an interpretation speed generally comparable to that of compiled code execution on a DEC-2060. The keys to achieving such high performance with small-sized hardware are a fully microcoded interpreter, implementation of a large hardware stack for variable binding, and multiple purpose registers designed to facilitate memory-access-intensive operations and byte manipulation. The language (TAO) on the workstation is a dialect of Lisp. TAO incorporates an object-oriented language and a logic programming language. The execution speed of either of the latter two types of languages is one-half that of Lisp. TAO supports multiple user operations and multiple process execution.< >
Scheduler 1-2-3 is an interactive analysis tool that can perform schedulability analysis for the development of real-time computing systems. The schedulability analysis can verify whether all hard real-time tasks in a...
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Scheduler 1-2-3 is an interactive analysis tool that can perform schedulability analysis for the development of real-time computing systems. The schedulability analysis can verify whether all hard real-time tasks in a target system will be completed by their deadlines at the system design phase. Scheduler 1-2-3 is a window-based stand-alone tool that can also be used as a synthetic workload generator in an integrated tool set that consists of a timing tool, a schedulability analyzer, and a real-time monitor/debugger.< >
The INSIGHT simulation language describes systems in a quick, simple, and compact fashion using a network representation. This description can be entered and simulated using novel interactive facilities that free the ...
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The INSIGHT simulation language describes systems in a quick, simple, and compact fashion using a network representation. This description can be entered and simulated using novel interactive facilities that free the user from learning specific syntax. Statistics summarizing the simulation are produced automatically, but can be greatly enhanced by various input models and output analysis mechanisms. Use of the language does not require programming and complex models use the descriptive features of simple ones, incorporating more elaborate specifications and more sophisticated concepts. INSIGHT is available for most computers and is portable across machines. The language has been extensively applied and its scope of applications has ranged from manufacturing to service environments. Using INSIGHT, the process of simulation modeling and the results from the simulations combine to provide "insight" into problem solving.
The proceedings contain 43 papers. The topics discussed include: BrouHaHa - a portable Smalltalk interpreter;experience and evolution of concurrent SmallTalk;producer a tool for translating Smalltalk-80 to objective-C...
ISBN:
(纸本)0897912470
The proceedings contain 43 papers. The topics discussed include: BrouHaHa - a portable Smalltalk interpreter;experience and evolution of concurrent SmallTalk;producer a tool for translating Smalltalk-80 to objective-C;INSIST: interactive simulation in Smalltalk;RAPID: prototyping control panel interfaces;Opus: a SmallTalk production system;OTM: applying objects to tasks;some experiments in object-oriented simulation;a pragmatic system for shared persistent objects;use of object-orientedprogramming in a time series analysis system;composite object support in an object-oriented database system;teaching object-orientedprogramming with the KEE system;concepts and experiments in computational reflection;delegation is inheritance;class modification in the gemstone object-oriented DBMS;dimensions of object-based language design;an information system based on distributed objects;metaclasses are first class : the ObjVlisp model;using objects to design and build radar ESM systems;experience with CommonLoops;Self: the power of simplicity;modules and type checking in PL/LL;and CLAM - an open system for graphical user interfaces.
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