[1] We examined the consistency of time series for stratospheric ozone obtained by ozonesondes, SAGE II, HALOE, and SBUV(/2) in the northern extratropics and find excellent agreement for interannual variability and trends of ozone for 50–12.5 hPa over Europe. Ozonesonde, SAGE, and HALOE data agree well for 200 hPa–12.5 hPa. Ozone in the past few years is 6% below values in the early 1980s for 8...

Several new algorithms for camera-based fall detection have been proposed in the literature recently, with the aim to monitor older people at home so nurses or family members can be warned in case of a fall incident. However, these algorithms are evaluated almost exclusively on data captured in controlled environments, under optimal conditions (simple scenes, perfect illumination and setup of c...

Abstract In this work we show how the existence of long term variability in Variable Bit Rate (VBR) video traffic imposes the need of bandwidth renegotiation. In particular, two simple scenarios with a fixed renegotiation interval are considered. Using a real MPEG trace the renegotiation scheme is evaluated to prove its benefits in terms of bandwidth gain and quality of service. The problem of ...

Introduction: There is data to indicate that there is substantial variability in ADC values of the brain between 1.5T and 3T. To our knowledge, there is no currently published data comparing 1.5 to 3T SS EPI in the abdomen, particularly in terms of ADC reproducibility and image quality. In this study, we performed DWI of healthy volunteers at both 1.5T and 3T using low and high b-values to asse...

The variability in voice quality is a critical factor in most of speech-related applications, but studies regarding this variability are scarce due to the absence of an adequate database. Based on the newly developing database, this study examines the effect of withinand between-speaker variability on speaker recognition systems. The preliminary results with a subset of the database show that v...

We denote as QoS-max the control of a request processing system to try to maximize QoS qualities and we focus on external, non-intrusive approaches with statistics on readily measurable quantities. In order to do this, the controller characterizes requests in terms of response times (or resource use) and uses that characterization to try to achieve QoS-max. However, measures vary both between d...

Mobile computing is a domain in great expansion. Wireless networks and Portable Information Appliances (PIAs) are developing very rapidly. More and more mobile users would like to perform their multimedia applications with the same facility as on their desktop station. Use of such applications in a mobile environment raises new challenges. These applications are interactive and extremely costly...

Traditional air quality monitoring relies on point measurements from a small number of high-end devices. The recent growth in low-cost air sensing technology stands to revolutionize the way in which air quality data are collected and utilized. While several technologies have emerged in the field of low-cost monitoring, all suffer from similar challenges in data quality. One technology that show...

Following a brief discussion on various aspects of data quality, possible methods are examined for the detection of errors in a spatial database. Using examples, we introduce the consistency checking method based on spatial relationships among neighboring objects and attribute relationships among map layers from different sources. Using logical relationships among spatial neighborhoods and amon...

We analyze the welfare impacts of price discrimination in a two-dimensional spatial differentiation model. Consumer information of varying qualities is available on one dimension which allows firms to price discriminate, and better information leads to more refined price discrimination. We find that as information quality improves, firms’ profits monotonically increase while consumer surplus an...