This paper describes the detection and identification of cracking severity in a reinforced concrete beam using modal data. Experimental modal test was performed on the beam before and after application of load of increasing intensity to induce a single crack at a fixed location. Modal parameters extracted were categorised into hvo groups, namely local response parameter (mode shape data) and gl...

In philosophical logic necessity is usually conceived as a sentential operator rather than a predicate. An intensional sentential operator does not allow one to express quantified statements such as ‘There are necessary a posteriori propositions’ or ‘All laws of physics are necessary’ in first-order logic in a straightforward way, while they are readily formalised if necessity is formalised by ...

It is well known that modal satisfiability is PSPACEcomplete [Lad77]. However, the complexity may decrease if we restrict the set of propositional operators used. Note that there exist an infinite number of propositional operators, since a propositional operator is simply a Boolean function. We completely classify the complexity of modal satisfiability for every finite set of propositional oper...

In this paper we introduce a new type of knowledge operator, called evidencebased knowledge, intended to capture the constructive core of common knowledge. An evidence-based knowledge system is obtained by augmenting a multi-agent logic of knowledge with a system of evidence assertions t :φ (“t is an evidence for φ”) based on the following plausible assumptions: 1) each axiom has evidence; 3) e...

Topic of the paper is Q-logic—a logic of agency in its temporal and modal context. Q-logic may be considered as a basal logic of agency since the most important stit-operators discussed in the literature can be defined or axiomatized easily within its semantical and syntactical framework. Its basic agent dependent operator, the Q-operator (also known as ∆or cstit-operator), which has been discu...

Memory logics are modal logics whose semantics is specified in terms of relational models enriched with additional data structure to represent memory. The logical language is then extended with a collection of operations to access and modify the data structure. In this paper we study their satisfiability and the model checking problems. We first give sound and complete tableaux calculi for the ...

In this paper we introduce a new type of knowledge operator, called evidencebased knowledge, intended to capture the constructive core of common knowledge. An evidence-based knowledge system is obtained by augmenting a multi-agent logic of knowledge with a system of evidence assertions t :φ (“t is an evidence for φ”) based on the following plausible assumptions: 1) each axiom has evidence; 3) e...

The temporal updating of an agent’s beliefs in response to a flow of information is modeled in a simple modal logic that, for every date t, contains a normal belief operator Bt and a non-normal information operator It which is analogous to the ‘only knowing’ operator discussed in the computer science literature. Soundness and completeness of the logic are proved and the relationship between the...

We explore the modal possibility operator and its dual necessity operator in qualitative data analysis , and show that it (quite literally) complements the derivation operator of formal concept analysis; we also propose a new generalisation of the rough set approximation operators. As an example for the applicability of the concepts we investigate the Morse data set which has been frequently st...

The temporal updating of an agent’s beliefs in response to a flow of information is modeled in a simple modal logic that, for every date t, contains a normal belief operator Bt and a non-normal information operator It which is analogous to the ‘only knowing’ operator discussed in the computer science literature. Soundness and completeness of the logic are proved and the relationship between the...