We enumerate all possible types of spacetime causal structures that can appear in static, spherically symmetric configurations of a self-gravitating, real, nonlinear, minimally coupled scalar field φ in general relativity, with an arbitrary potential V (φ) , not necessarily positive-definite. It is shown that a variable scalar field adds nothing to the list of possible structures with a constan...

The Web offers many tools a firm can explore to reap the benefits of this rich medium. Both practitioners and scholars are beginning to investigate ways to take full advantage of the techniques used in site promotion (Berthon et al., 1996; Ducoffe, 1996; Coyle & Thorson, 2001). These techniques may include the overall structure of the online retailing interface (Westland & Au, 1998), and such i...

This article describes an assistant interface to design and produce pop-up cards. A pop-up card is a piece of folded paper from which a three-dimensional structure pops up when opened. The authors propose an interface to assist the user in the design and production of a pop-up card. During the design process, the system examines whether the parts protrude from the card or whether the parts coll...

Purpose The “pop-up” epithet has become a synonym for virtually any temporary event in range of commercial, non-commercial and cultural contexts within the urban spatial arena. This paper aims to discuss role pop-up concept space, address question articulated Call Papers this special issue, whether “everywhere needs marketplace”. Design/methodology/approach authors review sources – both academi...