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Erik Rosén Jan-Erik Källhammer Dick Eriksson Matthias Nentwich Rikard Fredriksson Kip Smith 《Accident; analysis and prevention》2010,42(6):1949-1957
The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40°. Increasing the field of view further led to only marginal improvements in effectiveness. 相似文献
975.
Jung-Jung Su Matthias J. Graf Alexander V. Balatsky 《Journal of Low Temperature Physics》2010,159(3-4):431-440
We model the low-temperature specific heat of solid 4He in the hexagonal closed packed structure by invoking two-level tunneling states in addition to the usual phonon contribution of a Debye crystal for temperatures far below the Debye temperature, T<Θ D /50. By introducing a cutoff energy in the two-level tunneling density of states, we can describe the excess specific heat observed in solid hcp 4He, as well as the low-temperature linear term in the specific heat. Agreement is found with recent measurements of the temperature behavior of both specific heat and pressure. These results suggest the presence of a very small fraction, at the parts-per-million (ppm) level, of two-level tunneling systems in solid 4He, irrespective of the existence of supersolidity. 相似文献
976.
uSafe: A privacy-aware and participative mobile application for citizen safety in urban environments
Delphine Christin Christian Roßkopf Matthias Hollick 《Pervasive and Mobile Computing》2013,9(5):695-707
Recent mobile applications empower citizens to monitor noise pollution or report on features of their urban environment. One important aspect of urban life has, however, not been sufficiently addressed, namely the safety of citizens. We present a privacy-aware application called uSafe, in which users indicate how safe they feel in geographical locations. These feelings are then consolidated into summary maps accessible by other users and urban planners. We evaluate our concept with a questionnaire-based study involving 183 participants. The results confirm the utility of uSafe and show that privacy protection is a decisive factor in their decision to contribute to it. 相似文献
977.
Alexander Alexandrov Rico Bergmann Stephan Ewen Johann-Christoph Freytag Fabian Hueske Arvid Heise Odej Kao Marcus Leich Ulf Leser Volker Markl Felix Naumann Mathias Peters Astrid Rheinländer Matthias J. Sax Sebastian Schelter Mareike Höger Kostas Tzoumas Daniel Warneke 《The VLDB Journal The International Journal on Very Large Data Bases》2014,23(6):939-964
We present Stratosphere, an open-source software stack for parallel data analysis. Stratosphere brings together a unique set of features that allow the expressive, easy, and efficient programming of analytical applications at very large scale. Stratosphere’s features include “in situ” data processing, a declarative query language, treatment of user-defined functions as first-class citizens, automatic program parallelization and optimization, support for iterative programs, and a scalable and efficient execution engine. Stratosphere covers a variety of “Big Data” use cases, such as data warehousing, information extraction and integration, data cleansing, graph analysis, and statistical analysis applications. In this paper, we present the overall system architecture design decisions, introduce Stratosphere through example queries, and then dive into the internal workings of the system’s components that relate to extensibility, programming model, optimization, and query execution. We experimentally compare Stratosphere against popular open-source alternatives, and we conclude with a research outlook for the next years. 相似文献
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979.
Heribert Warzecha Daniela Ferme Markus Peer Andreas Frank Matthias Unger 《Journal of Bioscience and Bioengineering》2010,109(3):288-290
In this study we have expanded the metabolic potential of plant cell suspension cultures by introducing active human cytochrome P450 monooxygenase 3A4 into tobacco cells. Exogenously supplied loratadine was metabolized in a 3A4-specific manner, showing the capacity of this system for the generation of metabolites. 相似文献
980.
Quenched solid density functional theory (QSDFT) model for characterization of mesoporous carbons using nitrogen adsorption is extended to cylindrical and spherical pore geometries. The kernels of theoretical isotherms in the range from 0.4 to 50 nm are constructed accounting for different possible variations of the pore shapes in micropore and mesopore regions. The results of QSDFT method are illustrated with experimental data on adsorption on novel CMK-3 and 3DOm carbons. The proposed method is recommended for pore size distribution calculations for micro–mesoporous carbons obtained through various templating mechanisms. 相似文献