Reliable predictors of reduced redundancy test performance: The interaction between lexical bonds and test takers’ depth and breadth of vocabulary knowledge

The present study intended to investigate whether test takers’ breadth and depth of vocabulary knowledge can contribute to their efficient use of lexical bonds while restoring damaged texts in reduced redundancy tests. Moreover, the moderating role of general language proficiency was investigated in this interaction. In so doing, Vocabulary Levels Test (VLT), Word Associates Test (WAT), and a series of C-tests with high and low lexical bonds were administered to two groups of 85 upper-intermediate and 50 lower-intermediate EFL learners. Results of multiple regression analyses indicated the following: (a) breadth and depth of vocabulary knowledge played dissimilar roles for test takers with different levels of language proficiency; (b) depth of vocabulary knowledge was a better predictor for high-bond texts; and (c) test takers with higher levels of language proficiency made more efficient use of lexical bonds as contextual cues. The findings point to the necessity of improving learners’ depth of vocabulary knowledge, especially at lower levels of language proficiency where vocabulary knowledge is mostly a matter of size rather than quality.

A new method for the redundancy analysis of Petri net-based liveness enforcing supervisors

The deadlock control of flexible manufacturing systems (FMSs) has been widely studied in the literature. Petri nets (PNs) are extensively used as a tool for modelling, analysis and controller synthesis of such systems. In general, Petri-net-based liveness enforcing supervisors (LESs) include control places ( CPs) together with their input/output arcs. It is well known that the methods proposed for computing CPs may provide redundant and necessary CPs. In this paper, a new method is proposed for redundancy test of CPs by means of supervisory control theory (SCT). The proposed method is based on the idea that after the removal of a CP from an LES, if the controlled model is still live, then the removed CP is redundant. The proposed method makes use of the TCT implementation tool of SCT. It is applicable to a PN-based LES consisting of a set of CPs. The applicability of proposed method is demonstrated by means of examples from the relevant literature. For some examples, the redundancy test provides more permissive behaviour with structurally simpler supervisors.

NC-ALGORITHMS FOR OPERATIONS ON BINARY DECISION DIAGRAMS

(Ordered) binary decision diagrams are a powerful representation for Boolean functions and are widely used in logical synthesis, verification, test pattern generation or as part of CAD tools. NC-algorithms are presented for the most important operations on this representation, e.g. evaluation for a given input, minimization, satisfiability, redundancy test, replacement of variables by constants or functions, equivalence test and synthesis. The algorithms have logarithmic run time on CRCW COMMON PRAMs with a polynomial number of processors.