Screen-readers |computer software that enables a visually impaired user to read the contents of a visual display| have been available for more than a decade. Screen-readers are separate from the user application. Consequently, they have little or no contextual information about the contents of the display. The author has used traditional screen-reading applications for the last ve years. The de...

Within the framework of their long term working memory theory, Ericsson and Kintsch (1995) propose that experts rapidly store information in long-term memory through two mechanisms: elaboration of long-term memory patterns and schemas and use of retrieval structures. They use chess players' memory as one of their most compelling sources of empirical evidence. In this paper, I show that evidence...

One-way hash chains have been the preferred choice, over the symmetric and asymmetric key cryptography, in security setups where efficiency mattered; despite the ephemeral confidentiality and authentication they assure. Known constructions of one-way chains (for example, SHA-1 based), only ensure the forward secrecy and have limitations over their length i.e., a priori knowledge of chain’s leng...

BACKGROUND The reduction of childhood mortality by vaccines has been one of the greatest public health successes of the past century. However, many targets for immunization remain uncontrolled, and new or improved vaccines are emerging to meet these challenges. OBJECTIVE To review the evolution of vaccination and take an objective look at current vaccine development technologies, thereby fram...

Ergonomic problems of surgical lighting systems have been indicated by surgeons; however, the underlying causes are not clear. The aim of this study is to assess the problems in detail. Luminaire use during 46 hours of surgery was observed and quantified. Furthermore, a questionnaire on perceived illumination of and usability problems with surgical luminaires was issued among OR-staff in 13 hos...

From the end of the 1990s onwards the digital divide, commonly defined as the gap between those who have and do not have access to computers and the Internet, has been a central issue on the scholarly and political agenda of new media development. This article makes an inventory of 5 years of digital divide research (2000–2005). The article focuses on three questions. (1) To what type of inequa...

Granger causality (GC) is one of the most popular measures to reveal causality influence of time series and has been widely applied in economics and neuroscience due to its simplicity and easy implementation. In this paper, we show that GC in time domain cannot correctly determine how strongly one time series influences the other when there is directional causality between two time series, that...