This study concentrates mainly on the 12-year time trends of annual average ion concentrations in bulk precipitation from 10 Estonian monitoring stations. Trends revealed by the nonparametric Mann-Kendall test mostly show a statistically significant decline and, according to the order of ion decline per year, three groups of stations could be differentiated: stations directly affected by an ind...

Indoor air pollution is an increasing health concern, especially in enclosed environments such as underground subway stations because of increased global usage by urban populations. This study measured the indoor air quality of underground platforms at 10 metro stations of the Taipei Rapid Transit system (TRTS) in Taiwan, including humidity, temperature, carbon monoxide (CO), carbon dioxide (CO...

The locations of emergency medical service and fire stations are of paramount importance in order to achieve an effective and reliable emergency response system. As communities grow and demographics change, it may become necessary to replace existing stations or add more stations to satisfy the increasing public demands for emergency responses. With its fast growing population, new urban develo...

We aimed to describe the human resources and apparatuses of community health service (CHS) in Tongliao City of China and investigate the differences between CHS centers and stations. Field investigations and questionnaire-based surveys were conducted in 120 CHS organizations of Tongliao City, which were selected by a stratified multistage random cluster sampling method. Data were collected on t...

Day-to-day fluctuations of the daily range of the geomagnetic field H at the equatorial electrojet stations Ancon (ANC, 77.0 W) and Sao Luis (SLZ, 44.2 W) are described for the period January–June 1993. The H field started increasing between midnight and sunrise, reaching a peak shortly before noon. The daily range of H was maximum during March and April and minimum during June. Regardless of t...

A system of referential stations ASG EUPOS launched in 2008 in Poland provides, among others, information regarding the changes of the stations’ vertical and horizontal coordinates. These changes can be related to the changes of tectonic plates. One can create models of the vertical and horizontal movements of the Earth’s crust. The changes of height of the referential stations are more difficu...

BACKGROUND The objective structure clinical examination (OSCE) has been used since the early 1970s for assessing clinical competence. There are very few studies that have examined the psychometric stability of the stations that are used repeatedly with different samples. The purpose of the present study was to assess the stability of objective structured clinical exams (OSCEs) employing the sam...

Carrier sense multiple access and its variants have been widely used in mobile ad hoc networks. However, most existing access mechanisms cannot guarantee quality for real-time traffic. This paper presents a distributed medium access control protocol that provides multiple priority levels for stations to compete for the wireless channel. One common channel is assumed to be shared by all stations...

Wireless technology usage is rapidly expanding and WiMAX technology is more widely used. The new WiMAX standard adopts relay stations (RS) for better QoS. Published researches on multi-hop relay networks concentrate on quality of service, stations resources distribution and management, as well as creating network topology for better service quality [1-4]. However no specific study conducted to ...

This paper presents a novel method to arrange wakeup schedule for sleeping stations such that the number of wakeup stations in each beacon interval is balanced in IEEE 802.11 wireless local area networks (WLANs). This method reduces the probability of collision and thus the station can save more power. Next, we consider how to poll the wakeup stations to send the PS-Poll frame to get back their...