Conjunctive query answering is an important DL reasoning task. Although this task is by now quite well-understood, tight complexity bounds for conjunctive query answering in expressive DLs have never been obtained: all known algorithms run in deterministic double exponential time, but the existing lower bound is only an EXPTIME one. In this paper, we prove that conjunctive query answering in AL...

We introduce new linear time algorithms for satisfiability of binary propositional theories (2-SAT), and for recognition and satisfiability of renamable Horn theories. The algorithms are based on unit resolution, and are thus likely easier to integrate within general SAT solvers than other graph-based algorithms.

With the increasing demand and popularity of multimedia streaming applications over the current Internet, manipulating MPEG streams in a real-time software manner is gaining more and more importance. In this work, we studied the synchronization problem that arises when a gateway changes the data content carried in an MPEG2 Transport stream. In short, the distance between original time stamps wi...

Welcoming the participants, Dr A.O. Lucas, Director, UNDP/WORLD BANK/WHO Special Programme for Research and Training in Tropical Diseases (TDR), pointed out that there were many immunological features in common between leprosy and tuberculosis. He noted that one of the four sections of the meeting arose out of the establishment by IMMLEP of a bank of monoclonal antibodies that recognize Mycobac...

1 (abstract) We analyze a discrete-time network of queues. The unit element of the network is a 2 2 buuered switch, which we regard as a system of two queues working in parallel. We show how to transform transition probability information from the output of one switch, or network stage, to the input of the next one. This is used to carry out a Markov time series input model to predict mean queu...

An algorithm for mapping every possible input pattern of a CMOS gate to an equivalent set of normalized inputs (inputs which have the same starting point and transition time) is presented. Such an algorithm is required in order to perform analytical modelling of CMOS gates and the obtained results are of excellent accuracy compared to SPICE simulations.

Economists have long argued that systems of marketable permits are a cost-effective means of regulating externalities. Though these ideas have only recently been implemented in the field of pollution control, transferable development rights (TDRs) have been used for decades by city planners in many locales. Most opponents of permit trading contest the granting of property rights to the originat...

Recently Papadimitriou has proposed a randomised ‘bit flipping’ method for solving the 2-satisfiability problem; and the author has proposed a randomised recolouring method which, given a 3-colourable graph, finds a 2-colouring of the vertices so that no triangle is monochromatic. Both methods involve finding a ‘bad’ configuration (unsatisfied clause, monochromatic triangle) and randomly changi...

We have updated our previous study on the possibility to observe the rare B S → μμ decay with detailed simulation of the TDR version of the CMS detector. The full simulation and reconstruction procedure has been done both for the signal and background. We improved our previous results on expected sensitivity using more sophisticated algorithms for the track and vertex reconstruction and tighter...

Internet broadcasting and streaming contents have recently been attracting a great deal of attention, despite their inadequate content quality. The demand for such services is projected to continue to increase in the near future, and streaming contents are expected to play a major role among applications for the next-generation Internet [1] [2]. With the further development of DVTS, it will cer...