This study explores buyers’ search and purchase behavior in an information-overloaded retail Electronic Marketplace (EMP). Two instrumental variables, i.e. number of visitors and number of sales for an item, are used to represent buyers’ search and purchase behavior. Price and reputation, two of the most frequently researched independent variables in EMP studies, are considered. The relationshi...

This paper discusses the descriptional complexity of generalized forbidding grammars in context of degrees, numbers of nonterminals and conditional productions, and a new descriptional complexity measure—an index—of generalized forbidding grammars.

In recent years, several systems have been proposed that learn the rules of a simple card or board game solely from visual demonstration. These systems were constructed for specific games and rely on substantial background knowledge. We introduce a general system for learning board game rules from videos and demonstrate it on several well-known games. The presented algorithm requires only a few...

Motivated by computer science challenges, we suggest to extend the approach and methods of nite model theory beyond nite structures. We study de nability issues and their relation to complexity on meta nite structures which typically consist of (i) a primary part, which is a nite structure, (ii) a secondary part, which is a (usually in nite) structure that can be viewed as a structured domain o...

The lattice E of c.e. sets is a popular object of study in Computability Theory [So87]. A principal fact about this lattice is the undecidability of its first-order theory Th(E). Moreover, Th(E) is known [HN98] to be m-equivalent to the first-order arithmetic Th(N) where N := (ω; +,×). The lattice E may be considered as the lattice of effectively open subsets of the discrete topological space ω...

Imposing an extensional uniformity condition on a non-uniform circuit complexity class C means simply intersecting C with a uniform class L. By contrast, the usual intensional uniformity conditions require that a resource-bounded machine be able to exhibit the circuits in the circuit family defining C. We say that (C,L) has the Uniformity Duality Property if the extensionally uniform class C∩L ...

The first step when forming the polynomial hierarchies of languages is to consider languages of the form KaL where K and L are over a finite alphabet A and from a given variety V of languages, a ∈ A being a letter. All such KaL’s generate the variety of languages BPol1(V ). We estimate the numerical parameters of the language KaL in terms of their values for K and L. These parameters include th...

We investigate the descriptional complexity of limited propagating Lindenmayer systems and their deterministic and tabled variants with respect to the number of rules and the number of symbols. We determine the decrease of complexity when the generative capacity is increased. For incomparable families, we give languages that can be described more efficiently in either of these families than in ...

Combining expressiveness and plainness in the design of web documents is a difficult task. Validation languages are very powerful and designers are tempted to over-design specifications. This paper discusses an offbeat approach: describing any structured content of any document by only using a very small set of patterns, regardless of the format and layout of that document. A segmentation model...