Methods for Computing LALR(k) Lookahead

Methods for constructing LALR(k) parsers are discussed. Algorithms for computing LALR(k)-lookahead are presented together with the necessary theory to prove their correctness. Firstly a special algorithm for the LALR(1) case is presented. Secondly a general LALR(k)-algorithm with k >= 1 is presented. Given an item and a state the algorithms compute their corresponding LALR-lookahead during a recursive traversal of the LR(0)-machine. Finally the LALR(k)-algorithm is generalised to compute LALR(k)-lookahead for all items and states visited during the recursive traversal performed by the former algorithms

Investigation into the design of a remote maintenance system for clinical analysers

This is a thesis study of the design considerations involved in interfacing medical analysers to computer systems for remote monitoring. Most medical analysers provide a serial port connection for interfacing to a computer. Due to the limitations of this physical link, it is necessary for the interfacing computer to be within a radius of several metres. This computer can perform all the data monitoring and processing of the medical analyser. Monitoring the operational performance of a medical analyser can assist in maintenance programs. If it relays relevant data to a remote computer, a powerful remote maintenance and monitoring system can be developed when the remote monitoring computer collects data from a number of remote medical analysers. To satisfy the demands of remote maintenance and monitoring the Transmission Control Protocol/Internet Protocol (TCP/P) network protocol was investigated. The existing worldwide base of support for this protocol on numerous platforms and its universal addressing scheme made it the preferred choice for “openness” concerns. The relative merits of User Datagram Protocol (UDP) and Transmission Control Protocol (TCP) were evaluated and the nature of the reliable stream service offered by TCP was selected as more appropriate to the medical environment where data loss is unacceptable. A Client/Server architecture was investigated with a central server and remote clients which were connected to clinical analysers. The monitoring computer local to an analyser connects to the server using the TCP/IP network protocol. This Client-Server configuration is particularly suited to the distributed nature of medical laboratories where instruments are typically not centralised and the lack of availability of powerful computers makes it necessary to resort to using simple computers locally to the instrument to relay data to the more powerful server computer. The work was carried out with the co-operation of the Central Pathology Laboratory of Saint James’s hospital in Dublin