The i s sue is whe the r human v i s u a l imagery can be r e p r e s e n t e d by symbo l i c s t r u c t u r e s and p r o c e s s e s . P r o t o c o l s o f t he t a s k o f i m a g i n i n g a pa th i n space were ana l yzed u s i n g a p r o d u c t i o n system i n t e r p r e t e r . A d e t a i l e d s i m u l a t i o n o f the s u b j e c t ' s b e h a v i o r w i t h i n t h e c o n ...

A program cal led " A M " is descr ibed which cai r ies on simple mathemat ics research : defining, and studying new concepts under the guidance of a large body of heuiist ic rules. The 250 h e u r K t u s communicate via an agenda mechanism, a g loba l p r i o r i t y queue of small bisk', for the program to pei f o i m and teasons why each task is plausible (e.g., "Find PENCRAHZTION. of ' p r...

inc lude all pr ime knots wi th 16 or fewer crossings. This r epresen t s more than a 130-fold increase in the number of t abu la ted knots s ince the last burs t of tabula t ion tha t t ook p lace in the early 1980s. With more than 1.7 mil l ion knots now in the tables, we hope that the census will serve as a r ich source of examples and coun te rexamples and as a genera l test ing ground for ...

The student activities fee will increase by $10 for the next academic year as a result of a proposal put forth by the executive cabinet of the Student Union in December. Next y ea r, the fee, w hich h a s no t been increased since the 1980s, will be $65. The new revenue will be divided up among stu­ dent organizations, w ith h a lf of it going to clubs. While the raise in the fee is not as high...

The react ions occurr ing at potent ia ls of the second reduct ion wave of die thyl fumara t e (DEF) in d ime thy l fo rmamide solutions, where a cur ren t dip is f r equen t ly observed in the vo l t ammograms in the absence of added pro ton donors, was invest igated, The over -a l l react ion order was de te rmined by ro t a t ing disk e lec t rode studies of the var ia t ion in the current a...

T h i s pape r d e s c r i b e s a p rog ram f o r i n t e r p r e t a t i o n o f o i l w e l l m e a s u r e m e n t s . Two t e c h n i q u e s have been merged f o r t h i s p u r p o s e : t h e e x p e r t sys tem t e c h n i q u e ( p r o d u c t i o n r u l e s ) w h i c h l e n d s i t s e l f t o t h e s y m b o l i c r e a s o n i n g a s p e c t o f t h e p r o b l e m and p a t t e...

Al research has developed an extensive collect ion of methods to solve state-space problems. Using the challenging domain of Sokoban, this paper studies the effect of search enhancements on program performance. We show that the current state of the ar t in AT generally requires a large p rog ramming and research effort into domain-dependent: methods to solve even moderately complex problems in ...

Some innovations, whose long history of success faded into the background in the course of time, come back in a refreshed form decades later initiated by marketing activities of some companies. In the field of information and communication technology (ICT) we can currently see a renaissance of virtualization. Already at the end of the 1960 s there had been mainframe computers originating from I...

Heterochromatin is late n 1953—the year that Watson and Crick published those findings " of considerable biological interest " —Howard and Pelc (1953) showed that DNA synthesis occurred in a discrete phase of the cell cycle. They had labeled DNA with radioactive phosphate. But better spatial localization of replication required a lower energy and thus more highly localized radioactive probe. Th...

La mort de Charles Péguy pendant la Première Guerre mondiale mit fin à son œuvre ainsi qu’à l’entreprise des Cahiers Quinzaine. Cet espace liberté intellectuelle n’a pas été le fruit du sacrifice d’un esprit étranger aux questions économiques mais résultat d’une gestion profondément attentive réalit&#...