We consider the problem of covering the complete r-uniform hypergraphs on n vertices using complete r-partite graphs. We obtain lower bounds on the size of such a covering. For small values of r our result implies a lower bound of Ω( e r r √ r n log n) on the size of any such covering. This improves the previous bound of Ω(rn log n) due to Snir [5]. We also obtain good lower bounds on the size ...

Subtype tests are an important issue in the implementation of object-oriented programming languages. Many techniques have been proposed but none of them perfectly fullfills the five requirements that we have identified: constant-time, linear-space, multiple inheritance, dynamic loading and inlining. In this paper, we propose to apply a well known technique, perfect hashing, and we show that it ...

This paper presents a comprehensive comparative analysis of the functions present, past and future perfect forms in standard Latvian Lithuanian based on two complementary types data: typological questionnaire devised for study EUROTYP project Lithuanian-Latvian parallel corpus. We analyse data qualitatively as well quantitatively demonstrate that Baltic languages show both similarities importan...

As the number of systems which offer annotations on digital documents increases, robust anchoring of annotations is a key challenge. It is especially important if the annotator lacks write-access to the document being annotated. For example, if someone makes an annotation on a web page today and the web page changes tomorrow, what happens to the annotation? One approach is simply to “orphan” th...

A linear (qd, q, t)-perfect hash family of size s in a vector space V of order qd over a field F of order q consists of a set φ1, . . . , φs of linear functionals from V to F with the following property: for all t subsets X ⊆ V there exists i ∈ {1, . . . , s} such that φi is injective when restricted to F . A linear (qd, q, t)-perfect hash family of minimal size d(t− 1) is said to be optimal. I...

The purpose of the present study was first to offer a tentative solution to the problems observed in writing pedagogy in Iran by devising a more comprehensive approach to genre-based writing instruction. In the second phase, a quasi-experimental research design was adopted to determine how effective the model was in writing instruction, compared with the traditional, product-oriented approach, ...

Super-simple designs are useful in constructing codes and designs such as superimposed codes and perfect hash families. Recently, Gronau et al determined the existence of super-simple (v, 5, 2)-BIBDs with possible exceptions of v ∈ {75, 95, 115, 135, 195, 215, 231, 285, 365, 385, 515}. In this article, we investigate the existence of a super-simple (v, 5, 4)-BIBD and show that such a design exi...