in this paper, the behavior of free vibrations and buckling of the sandwich panel with a flexible core was investigated using a new improved ‎high-order sandwich panel theory. in this theory, equations of motion were formulated based on shear stresses in the core. first-order shear deformation theory was ‎applied for the procedures. in this theory, for the first time, incompatibility problem of...

We propose a proof of the downward Löwenheim-Skolem that relies on strategies deriving from evaluation games instead of the Skolem normal forms. This proof is simpler, and easily understood by the students, although it requires, when defining the semantics of first-order logic to introduce first a few notions inherited from game theory such as the one of an evaluation game. 1998 ACM Subject Cla...

We develop the scheme of indefinite constraint databases using first-order logic as our representation language. When this scheme is instantiated with temporal constraints, the resulting formalism is more expressive than standard temporal constraint networks. The extra representational power allows us to express temporal knowledge and queries that have been impossible to express before. To make...

Sufficient conditions are provided for quantifier elimination to hold in a first-order theory. The conditions have two main purposes: (1) to ensure that satisfaction of existential formulas is reflected by an embedding; and (2) to guarantee the existence of a “minimal" model of the theory extending a model of the universal formulas entailed by the theory. The first goal is obtained by requiring...

I Abstract We are investigating the possibility of constructing meaningful and computationally efficient approximate reasoning methods for the first order logic. In particular, we study a situation when only certain aspects of the domain are of interest to the user. This is reflected by an equivalence relation defined on the domain of the knowledge base. The whole mechanism is called domain abs...

A team of agents is jointly able to achieve a goal if despite any incomplete knowledge they may have about the world or each other, they still know enough to be able to get to a goal state. Unlike in the single-agent case, the mere existence of a working plan is not enough as there may be several incompatible working plans and the agents may not be able to choose a share that coordinates with t...

Certain applications of logic to computer science, for example those discus: in [4], have the following features: only finite models are of interest, first-order logic is not sufficiently expressive. Accordingly, various extensions first-order logic have been proposed and analyzed for finite structures. " analysis often reveals connections with computational complexity, and ind some of the exte...

We investigate the possibility of improving the efficiency of reasoning through structure-based partitioning of logical theories, combined with partitionbased logical reasoning strategies. To this end, we provide algorithms for reasoning with partitions of axioms in first-order and propositional logic. We analyze the computational benefit of our algorithms and detect those parameters of a parti...

The idea to combine the advantages of function and logic programming has attracted many researches. Their work ranges from the integration of existing languages over higher-order logic to equational logic languages, where logic programs are augmented with equational theories. Recently, it has been proposed to handle those equational theories by complete sets of transformations. These transforma...