In the past, full-service stock brokerage firms had a strategic advantage over discount brokers because of the control full-service brokers had over the information provided to the customer. Full-service stockbrokers acted as information intermediaries in that they were able to capture residual value from the transfer of information to make a profit. Strategic vulnerability occurs, in this case...

One goal of genome projects is to systematically identify genes (1,2). The best current knowledge indicates that humans carry approximately 35000 genes. This number is an estimate that varies from expert to expert and range up to 100,000 (3-5). To anyone who has taken an elementary biology class, this ambiguity must seem strange. How hard can it be to count genes? After all, don't cells transla...

The braid group Bn is the mapping class group of an n-punctured disk. An n-braid is reducible if it has an invariant essential curve system in the punctured disk. We show that for some class of reducible braids (including split braids), finding a reduction system is as easy as finding one element in the ultra summit set.

At any stage in a well-run conversation, a certain amount is presupposed. The parties to the conversation take it for granted; or at least they purport to, whether sincerely or just “for the sake of the argument”. Presuppositions can be created or destroyed in the course of a conversation. This change is rule-governed, at least up to a point. The presuppositions at time r’ depend, in a way abou...

Adaptive navigation support normally attempts to make selecting a relevant hyperlink as easy as possible. However, in educational applications, this may have negative learning effects since selecting a link is sometimes an important educational problem for the student to solve. To provide appropriate scaffolding to students, it is necessary to understand how they navigate in hypermedia sites. B...

In a virtual university, advanced support for all aspects of handling assignments is needed. Homework assignments are particularly in need of help because communication between teachers and learners as well as between learners is not as easy as in presence universities. In this paper, we present an overview of the AT(x) approach (analyze-and-test) for automatically analyzing and testing program...

In this paper, we examine the evolution of the impact of non-elite journals. We attempt to answer two questions. First, what fraction of the top-cited articles are published in non-elite journals and how has this changed over time. Second, what fraction of the total citations are to non-elite journals and how has this changed over time. To answer these questions, we studied citations to article...

A concise outline of background is given on assistive methods for writing and communicating for non-speaking people, highlighting the role of efficient text entry in augmentative and alternative communication (AAC). AAC systems are designed to assist people with communication impairments to interact with others and to compose messages and other documents. Efficient text entry is therefore of gr...

This paper chronicles some issues that arose in attempting to implement two simple planners that interleave planning and execution. (For brevity, such planners will be called IPE planners.) The IPE planners are based on UCPOP (Barrett et al. 1993), a classic operator-based planner using goal-regression. Unfortunately, while the planners succeeded on very simple problems, they failed on problems...