BACKGROUND We plan to conduct a case-control study to investigate whether exposure to nitrogen dioxide (NO2) increases the risk of stroke. In case-control studies, selective participation can lead to bias and loss of efficiency. A two-phase design can reduce bias and improve efficiency by combining information on the non-participating subjects with information from the participating subjects. I...

In this paper, a classifier based on the positive Boolean function(PBF) is proposed for the supervised pattern classification. A PBF is exactly represented as one sum-of-product form without any negative components. The PBF possesses the well-known threshold decomposition and stacking properties. The classification errors can be calculated from the summation of the absolute errors incurred at e...

The work presented in this paper is intended as an introduction to a study being carried out at the University of Bristol in conjunction with the SEAS DTC and forms the basis for a PhD in aerospace engineering. The focus of the research is the design of control systems for small unmanned rotary wing vehicles which receive feedback signals from visual sensory devices to augment controllability. ...

This study has aimed to compare the effects of two types of form-focused instruction, i.e. de-contextualized focus-on-forms instruction versus meaning-centered contextualized focus-on-form instruction, on the development of grammatical knowledge of Iranian high-school students. Two groups of male high-school first graders participated in this study.  One group was taught through de-contextualiz...

This paper reviews the experience of Persian designers and planners for creating the most livableand greenery capital city in the hole region of Middle East throughout the 17th Century. New concepts of urban greendevelopment emerged in that time. Some of these ideas where extremely creative and vanguard from there era andstill some of them are the main theoretical basics of urban green planning...