In this paper we present a logic formalization of a model which allows us to represent, create and maintain a Learner Model for CSCL environments in a clear and adequate manner, in order to use it as the set of belief...
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ISBN:
(纸本)0769519156
In this paper we present a logic formalization of a model which allows us to represent, create and maintain a Learner Model for CSCL environments in a clear and adequate manner, in order to use it as the set of beliefs an agent holds about its user, supporting the effective collaboration between the learners in the community. Our model includes a representation method for the knowledge domain and the agent's beliefs about the learner, as well as an inference system. This system allows the agent to propose the learner adequate learning tasks, considering his own interest and possibilities and those of the other members of the community through the establishment of group-based Zones of Proximal Development. The model is formalized in Answer Sets programming, which gives an appropriate framework for dealing with non-monotonicity in disjunctive logic programs with negation.
Clones of logic functions form an algebraic lattice, which in the case of Boolean functions was completely described by *** in 1941. This lattice, often referred to as the Post Lattice, has been well studied from vari...
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ISBN:
(纸本)0769519180
Clones of logic functions form an algebraic lattice, which in the case of Boolean functions was completely described by *** in 1941. This lattice, often referred to as the Post Lattice, has been well studied from various angles, particularly, the generation of the Post Lattice by its subsets. This paper discusses the results about clones that are irreducible by means of meet- and/or join-operations of the lattice. We show that the join-irreducible clones generate the Post Lattice, and dually, the meet-irreducible clones generate the Post Lattice. We present a complete description of such generation in both cases. We observe that any clone can be presented as a join or meet of at most two irreducible clones. In the former case each clone is the join of at most four join-irreducible clones and in the latter case each clone is the meet of at most three meet- irreducible ones.
We investigate the application of abductive logic programming, an existing framework for knowledge representation and reasoning, for specifying the knowledge and behaviour of software agents that need to access resour...
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ISBN:
(纸本)3540140093
We investigate the application of abductive logic programming, an existing framework for knowledge representation and reasoning, for specifying the knowledge and behaviour of software agents that need to access resources in a global computing environment. The framework allows agents that need resources to join artificial societies where those resources are available. We show how to endow agents with the capability of becoming and ceasing to be members of societies, for different categories of artificial agent societies, and of requesting and being given or denied resources within societies. The strength of our formulation lies in combining the modelling and the computational properties of abductive logic programming for dealing with the issues arising in resource access within artificial agent societies.
This paper presents a logic based approach to hardware abstraction and composition based on the logic programming language Prolog. This is an attempt to satisfy the dual requirement of abstract hardware design and har...
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ISBN:
(纸本)0769519792
This paper presents a logic based approach to hardware abstraction and composition based on the logic programming language Prolog. This is an attempt to satisfy the dual requirement of abstract hardware design and hardware efficiency. Central to this approach is a hardware description environment called HIDE, which provides more abstract and elegant hardware descriptions and compositions than are possible in traditional hardware description languages such as VHDL or Verilog. The environment enables highly scaleable and parameterised composition of blocks using a small set of constructors e.g. 'horizontal' and 'vertical' for 2D circuit abstractions and the novel 'above' constructor for 3D circuit compositions. It also generates pre-placed configurations in EDIF (and VHDL) format for Xilinx FPGAs.
This paper considers the problem of synthesizing systems modeled by condition systems into microcontrollers. Condition system, a discrete event system model, can be naturely programmed into microcontrollers. Directly ...
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ISBN:
(纸本)0780376978
This paper considers the problem of synthesizing systems modeled by condition systems into microcontrollers. Condition system, a discrete event system model, can be naturely programmed into microcontrollers. Directly using incidence matrix and state equation to implement condition systems is not a good method for low-cost microcontrollers because of the lack of certain instructions and limited memory of the microcontrollers. An alternate logic algebra based method is presented and an example condition system is illustrated. By using this method, the corresponding assembly code will be easily created in a systematic way.
We integrate ontology languages and logic programming (LP) by extending disjunctive logic programs (DLPs) and their semantics in order to support inverses and an infinite universe, without introducing function symbols...
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ISBN:
(纸本)0769519938
We integrate ontology languages and logic programming (LP) by extending disjunctive logic programs (DLPs) and their semantics in order to support inverses and an infinite universe, without introducing function symbols. We show that this extension is still decidable, and can be used to simulate, on the one hand, answer set programming with a finite universe, and on the other hand, several expressive description logics (DLs), which can be seen as ontology languages. The integration leads to a "best of both worlds": from the LP side it inherits a flexible and intuitive representation of knowledge, whereas the DLs side provides the possibility to represent infinite knowledge.
Prioritized logic programs (PLPs) have a mechanism of representing priority knowledge in logic programs. The declarative semantics of a PLP is given as preferred answer sets which are used for representing nonmonotoni...
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ISBN:
(数字)9783540398134
ISBN:
(纸本)3540201017
Prioritized logic programs (PLPs) have a mechanism of representing priority knowledge in logic programs. The declarative semantics of a PLP is given as preferred answer sets which are used for representing nonmonotonic reasoning as well as preference abduction. From the computational viewpoint, however, its implementation issues have little been studied and no sound procedure is known for computing preferred answer sets of PLPs. In this paper, we present a sound and complete procedure to compute all preferred answer sets of a PLP in answer set programming. The procedure is based on a program transformation from a PLP to a logic program and is realized on top of any procedure for answer set programming. The proposed technique also extends PLPs to handle dynamic preference and we address its application to legal reasoning.
We show how role-based access control (RBAC) and temporal RBAC (TRBAC) policies may be formally represented and translated into PL/SQL code to implement practical access control policies to protect Oracle SQL database...
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ISBN:
(纸本)1402075413
We show how role-based access control (RBAC) and temporal RBAC (TRBAC) policies may be formally represented and translated into PL/SQL code to implement practical access control policies to protect Oracle SQL databases. Performance results for an implementation of a TRBAC policy in PL/SQL are presented.
Spurred by the development of Universidade de Evora's Integrated Information System (SIIUE) and on the authors' present research interests came the idea of a Natural Language Analysis System, which would provi...
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ISBN:
(纸本)354000680X
Spurred by the development of Universidade de Evora's Integrated Information System (SIIUE) and on the authors' present research interests came the idea of a Natural Language Analysis System, which would provide a simple interface for getting access to existent information. This information is stored mainly in multiple object-relational databases. The system was built using a logic programming based approach as an application of the logic programming development tool ISCO. With it, the system can uniformly access heterogeneous external relational databases while doing syntactic and semantic sentence parsing. Although the main data sources accessed by the system described herein are the SIIUE databases, other existing databases can be integrated to be used by this system.
Visualization has played a significant role in understanding the behavior of distributed programs. We propose a visualization that shows message exchanges in distributed logic programs using the Program Structure View...
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ISBN:
(纸本)1892512459
Visualization has played a significant role in understanding the behavior of distributed programs. We propose a visualization that shows message exchanges in distributed logic programs using the Program Structure View in NaraView. The behavior of distributed logic programs is easily visualized using the Program Structure View since the messages have three parametric factors: time, derivation, and hierarchical level.
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