Jason McC. Smith

SPQR: flexible automated design pattern extraction from source code

Previous automated approaches to discovering design patterns in source code have suffered from a need to enumerate static descriptions of structural and behavioral relationships, resulting in a finite library of variations on pattern implementation. Our approach, system for pattern query and recognition, or SPQR, differs in that we do not seek statically to encode each variant of the patterns that we wish to find. Our system finds pattern variants that were not explicitly defined, but instead are inferred dynamically during code analysis by a theorem prover, providing practical tool support for software construction, comprehension, maintenance, and refactoring. We use a logical inference system to reveal large numbers of patterns and their variations from a small number of definitions by encoding in a formal denotational semantics a small number of fundamental OO concepts (elemental design patterns), encode the rules by which these concepts are combined to form patterns (reliance operators), and encode the structural/behavioral relationships among components of objects and classes (rho-calculus). A chain of fully automated tools provides a path from source code to revealed patterns. We describe our approach in this paper with a concrete example to drive the discussion, accompanied by formal treatment of the foundational topics.

An orthogonal taxonomy for hyperlink anchor generation in video streams using OvalTine

As dynamically linked content follows the progression of statically linked media into the realm of video, new opportunities for link creation become apparent. In this paper we describe a real-time video hypermedia system with user-definable linkage areas, in a distributed collaborative environment. We also investigate the extension of such a system to automated link creation in video streams. In the process, we identify and describe orthogonal issues of hypervideo anchor creation. An example system, OvalTine, has been produced to illustrate several potential uses through configuration of an extended video conferencing application on the SGI O2 platform.

FaceSpace: endo- and exo-spatial hypermedia in the transparent video facetop

The Transparent Video Facetop is a novel user interface concept that supports not only single-user interactions with a PC, but also close pair collaborations, such as that found in collaborative Web browsing, in distributed pair programming and in remote medicine. We recently demonstrated the Vis-a-Vid Facetop prototype as a single-user GUI for manipulating the elements of a traditional WIMP desktop [21]. In this paper we introduce FaceSpace, a Facetop-based hypermedia system that combines structure and functionality of both spatial and ubiquitous hypertext. FaceSpace eliminates camera registration errors due to dynamic object tracking and user self-image feedback. FaceSpace had two forms of linking that combine spatial hypermedia with ubiquitous hypermedia: Like an exo-skeleton provides an organism with structure from without, exo-spatial hypertext has the spatial structure applied over the ubiquity of the users real-world environment. Endo-spatial hypertext has the spatial structure derived from and attached to the elements of the users domain. Endo-spatial hypertext is an integral concept in systems that have been classified as ubiquitous hypertext; exo-spatial is unique to FaceSpace in current hypertext systems.

Support for Distributed Pair Programming in the Transparent Video Facetop

The Transparent Video Facetop is a novel user interface concept that supports not only single-user interactions with a PC, but also close pair collaborations, such as that found in collaborative Web browsing, remote medicine, and in distributed pair programming. In this paper we discuss the use of a novel video-based UI called the Facetop [16] for solving several problems reported to us by teams doing distributed pair programming. Specifically, the Facetop allows a distributed pair to recapture some the facial expressions and face-to-face communications contact lost in earlier distributed sessions. It also allows members of a distributed pair to point conveniently, quickly, and naturally to their shared work, in the same manner (manually) that they do when seated side-by-side. Our results enhance the ability of organizations to do effective XP-style agile development with distributed teams.

Semi-automated Hyperlink markup for archived video

1. MOTIVATION AND BACKGROUND One of the problems keeping video from being a fully first-class data component of hypermedia documents is the difficulty of treating the objects depicted in video as identifiable, linkable content. Rather, video tends to be manipulated as frames of pixels with no further subdivisions. We previously reported on the realtime OvalTine system [1], in which we showed the creation and maintenance of links in real-time video streams such as teleconferences. This paper presents our continuing work with this system, demonstrating the use of the basic real-time image tracking algorithms for use in automated markup of stored video data. There is increasing interest in video data being incorporated in hypermedia structures. Digital libraries are growing in popularity and scope, and video is an important component of such archives. All major news services have vast video archives, valuable “footage” that would be of use in education, historical research, even entertainment.