background and purpose: sample size and its determination is one of the most important problems in health researches. calculating sample size for prevalence studies is one of the common questions of sample size topics. minimum sample size with least complexity is desirable in order to achieve the basic goal of these studies. this study aims to compare two formulas of sample size calculation for...

There are number of software environment available to conduct lighting simulations to support researchers and designers. This paper compares and analyses performance of four lighting simulation programs (AGI32, DIALux, RADIANCE and RELux), which are dedicated to provide physically accurate lighting calculation. Along with the evaluation of modeling ability and software features two significant ...

virtual water adds a new dimension to crop trades and provides a new way of thinking about water scarcity. a systematic analysis of virtual water flows requires integration of all critical drivers of virtual water flows under a single consistent framework. the aim of this study was to assess virtual water flows related to trades of grain crops (wheat, corn, rice, and coarse cereals) and their i...

Further studies on computer-based perception by vision modelling are described. The visual perception is mathematically modelled, where the model receives and interprets visual data from the environment. The perception is defined in probabilistic terms so that it is in the same way quantified. At the same time, the measurement of visual perception is made possible in real-time. Quantifying visu...

A 915-MHz boundary layer wind profiler with radio acoustic sounding system (RASS) was sited 8 km from a very tall (450 m) television transmitting tower in north-central Wisconsin during the spring, summer, and autumn of 1995. The profiler measured wind means and variances, and the RASS attachment measured virtual temperature. These quantities are compared to measurements from cup and sonic anem...

China has dramatically increased its virtual water import over recent years. Many studies have focused on the quantity of traded virtual water, but very few go into analysing geographic distribution and the properties of China’s virtual water trade network. This paper provides a calculation and analysis of the crop-related virtual water trade network of China based on 27 major primary crops bet...

Hydrologic models of watersheds often represent complex systems which are difficult to understand regarding to their structure and dynamics. Virtual watersheds, i.e. watersheds which exist only in the virtual reality of a computer system, are an approach to simplify access to this real-world complexity. In this study we present the virtual watershed KIELSHED-1, a 117 km2 v-shaped valley with gr...

This paper presents a hybrid conversation group of talking heads, and discusses some solutions concerning emotions and social-emotional signs in more detail. A hybrid conversation group consists of real and virtual members, which meet to discuss some specific theme. The use of such a group, together with digital storytelling techniques, is a promising way of engaging the user in the exploration...