35 research outputs found
Development and validation of tools for the implementation of European air quality policy in Germany (Project VALIUM)
Development and validation of tools for the implementation of european air quality policy in Germany (Project VALIUM)
International audienceIn the framework of the German Atmospheric Research Program AFO-2000 a system of consistent coupled numerical models has been developed. The purpose of the model system is to serve as a tool for the execution of European urban air quality regulations. A consortium with the acronym VALIUM was formed, which consisted of German research institutes, environmental consultancies and an environmental agency. A substantial part of the VALIUM program was devoted to the generation of a set of high quality data for the validation of the numerical model system. The validation data are based on a combination of field studies, tracer experiments and corresponding wind tunnel experiments. The field experiments were carried out inside and around a street canyon in a city district of Hanover/Germany. After a brief introduction to the VALIUM project a summary of the main results will be given
Mental health and the impact of ubiquitous technologies
This Theme issue focuses on the emerging research of ubiquitous technologies to support mental health. So far, the majority of work presented in the field of ubiquitous healthcare has focused on supporting people affected by somatic diseases. However, increasing number of diseases affecting mental health has prompted research on technologies to support people suffering from these diseases. This Theme issue provides a number of examples of research on the potential impact of ubiquitous technologies in the field of mental health
Recognition of Crowd Behavior from Mobile Sensors with Pattern Analysis and Graph Clustering Methods
Mobile on-body sensing has distinct advantages for the analysis and
understanding of crowd dynamics: sensing is not geographically restricted to a
specific instrumented area, mobile phones offer on-body sensing and they are
already deployed on a large scale, and the rich sets of sensors they contain
allows one to characterize the behavior of users through pattern recognition
techniques.
In this paper we present a methodological framework for the machine
recognition of crowd behavior from on-body sensors, such as those in mobile
phones. The recognition of crowd behaviors opens the way to the acquisition of
large-scale datasets for the analysis and understanding of crowd dynamics. It
has also practical safety applications by providing improved crowd situational
awareness in cases of emergency.
The framework comprises: behavioral recognition with the user's mobile
device, pairwise analyses of the activity relatedness of two users, and graph
clustering in order to uncover globally, which users participate in a given
crowd behavior. We illustrate this framework for the identification of groups
of persons walking, using empirically collected data.
We discuss the challenges and research avenues for theoretical and applied
mathematics arising from the mobile sensing of crowd behaviors
Detailed design features of a new wind tunnel for studying the effects of thermal stratification
Gait Monitoring for Early Neurological Disorder Detection Using Sensors in a Smartphone: Validation and a Case Study of Parkinsonism
A new simplified NO/NO2 conversion model under consideration of direct NO2-emissions
Although many German monitoring sites report declines of NOx concentrations, NO2-concentrations actually stagnate or even increase quite often. Various analyses have identified the altered compositions of nitrogen oxides (NO2/NOx-ratio) emitted by motor vehicles (resulting in an increase of primary NO2-emissions) as well as the chemical environmental conditions (mainly ground level ozone) as the main causes. The chemical conversion of NO to NO2 is often parameterized in dispersion calculations of exhaust emissions. A widely applied conversion model is the so-called Romberg approach from 1996. However, the Romberg approach has to be re-evaluated to accommodate the above-mentioned conditions. This article presents an adjustment to the Romberg approach in accordance with the measured data from 2000 to 2006, taking into consideration substantially higher NO2/NOx-ratios especially for higher NOx-concentrations. Model calculations with OSPM (Operational Street Pollution Model) including its internal chemistry module are able to reproduce very well the trends in the measured annual NO2-concentrations over a 10 year period. The relevant parameters for variations between the years are the NOx-emissions, primary NO2-emissions, ozone concentrations, wind conditions, and background concentrations. A simplified chemistry model based on annual mean NOx- and NO2-concentrations, and background ozone concentrations, as well as primary NO2-emissions is presented as a better method than the updated Romberg approach. This model simulates the annual mean NO2-concentrations much more accurately than the conventional and the updated Romberg approaches
A simplified NO/NO2 conversion model under consideration of direct NO2-emissions
Although many German monitoring sites report declines of NOx concentrations, NO2-concentrations actually stagnate or even increase quite often. Various analyses have identified the altered compositions of nitrogen oxides (NO2/NOx-ratio) emitted by motor vehicles (resulting in an increase of primary NO2-emissions) as well as the chemical environmental conditions (mainly ground level ozone) as the main causes. The chemical conversion of NO to NO2 is often parameterized in dispersion calculations of exhaust emissions. A widely applied conversion model is the so-called Romberg approach from 1996. However, the Romberg approach has to be re-evaluated to accommodate the above-mentioned conditions. This article presents an adjustment to the Romberg approach in accordance with the measured data from 2000 to 2006, taking into consideration substantially higher NO2/NOx-ratios especially for higher NOx-concentrations. Model calculations with OSPM (Operational Street Pollution Model) including its internal chemistry module are able to reproduce very well the trends in the measured annual NO2-concentrations over a 10 year period. The relevant parameters for variations between the years are the NOx-emissions, primary NO2-emissions, ozone concentrations, wind conditions, and background concentrations. A simplified chemistry model based on annual mean NOx- and NO2-concentrations, and background ozone concentrations, as well as primary NO2-emissions is presented as a better method than the updated Romberg approach. This model simulates the annual mean NO2-concentrations much more accurately than the conventional and the updated Romberg approaches.An vielen deutschen Messstationen wird zwar ein RĂŒckgang der NOx-Konzentrationen, aber hĂ€ufig eine Stagnation der NO2-Konzentrationen oder gar deren Anstieg beobachtet. Verschiedene Untersuchungen identifizierten als Hauptursachen eine geĂ€nderte Zusammensetzung der seitens der Kraftfahrzeuge emittierten Stickoxide (NO2/NOx-VerhĂ€ltnis) und die daraus folgende Erhöhung der primĂ€ren NO2-Emissionen des KfzVerkehrs sowie die chemischen Umgebungsbedingungen (insbesondere bodennahes Ozon). Die chemische Umwandlung von NO in NO2 wird innerhalb von Ausbreitungsrechnungen fĂŒr Autoabgase oft parametrisiert. Ein hĂ€ufig angewendetes Konversionsmodell stellt hierbei die so genannte Romberg-Formel aus dem Jahr 1996 dar. Unter den o. g. verĂ€nderten Randbedingungen steht die Romberg-Formel derzeit auf dem PrĂŒfstand. Eine Anpassung der Romberg-Formel an Messdaten aus den Jahren 2000 bis 2006 wird aufgezeigt. Diese zeigt insbesondere bei hohen NOx-Konzentrationen deutlich höhere NO/NO2-Umwandlungsraten. Modellrechnungen mit OSPM inkl. nachgeschalteten Chemiemodell können die Trends der NO2-Jahresmittelwerte ĂŒber einen Zeitraum von 10 Jahren gut reproduzieren. Die relevanten EinflussgröĂen auf die Variationen zwischen den Jahren sind die NOx-Emissionen, die primĂ€ren NO2-Emissionen, die Ozonkonzentrationen, die WindverhĂ€ltnisse und die Hintergrundbelastungen. Als möglichen Ersatz fĂŒr die Romberg-Formel bzw. dessen Aktualisierung wird ein vereinfachtes Chemiemodell auf Basis der Jahresmittelwerte von NOx-, NO2 und Ozon-Hintergrundbelastung sowie primĂ€rer NO2-Emission vorgestellt. Dieses kann die Trends in den NO2-Jahresmittelwerten deutlich besser abbilden als der Romberg- bzw. der aktualisierte Rombergansatz