Aircraft Based Measurements of Sulfur Dioxide Pollution Plumes in the Free Troposphere

Sulfur dioxide pollution plumes have been investigated in the free troposphere onboard a research aircraft, using Chemical Ionization Mass Spectrometry (CIMS). The measurements have been carried out during the MEGAPLUME campaign in spring 2006 at the German Aerospace Center (DLR, Oberpfa enhofen, Germany), and during the international African Monsoon Multidisciplinary Analysis (AMMA) campaign in August 2006 inWest Africa (Ouagadougou, Burkina Faso). Sulfur dioxide is an important precursor gas of sulfuric acid which strongly contributes to aerosol formation. Aerosol particles directly and indirectly a ect our climate in various ways. Two di erent pollution plumes will be discussed in this work: a plume from Southeast Asia that had reached Europe after crossing the Paci c and Atlantic ocean, and an extended biomass burning layer o the coast of Ghana. The upward transport of sulfur dioxide in large convective thunderstorms during the African Monsoon has been investigated as another part of the AMMA campaign

Kontinuierliche Verarbeitung von Datenströmen zur Berechnung von Objektempfehlungen auf Basis von Datenstromqueries

Empfehlungssysteme filtern aus einer großen und unübersichtlichen Menge an Objekten (z.B. Nachrichtenartikel) eine Auswahl für eine Benutzerin bzw. einen Benutzer als möglichst nützliche Empfehlung heraus. Die Berechnung von relevanten Objekten erfolgt in der Regel durch die Analyse von Verhalten der Personen (z.B. Seitenaufrufe, Käufe). Dabei spielt in vielen Anwendungen nicht nur das über einen langen Zeitraum beobachtete Verhalten der Personen, sondern auch das aktuelle Verhalten in einem kurzen Zeitfenster eine Rolle. In dieser Arbeit wird untersucht, wie die Technologie der Datenstrommanagementsysteme für die Umsetzung von Empfehlungssystemen eingesetzt werden kann, um Empfehlungen kontinuierlich auf Grundlage des aktuellsten Datenbestandes zu berechnen. Ergebnis sind Konzepte sowie ein Framework zur Umsetzung eigener Empfehlungssysteme auf Basis von Datenstrommanagementsystemen

The Parallel Meaning Bank: Towards a Multilingual Corpus of Translations Annotated with Compositional Meaning Representations

The Parallel Meaning Bank is a corpus of translations annotated with shared, formal meaning representations comprising over 11 million words divided over four languages (English, German, Italian, and Dutch). Our approach is based on cross-lingual projection: automatically produced (and manually corrected) semantic annotations for English sentences are mapped onto their word-aligned translations, assuming that the translations are meaning-preserving. The semantic annotation consists of five main steps: (i) segmentation of the text in sentences and lexical items; (ii) syntactic parsing with Combinatory Categorial Grammar; (iii) universal semantic tagging; (iv) symbolization; and (v) compositional semantic analysis based on Discourse Representation Theory. These steps are performed using statistical models trained in a semi-supervised manner. The employed annotation models are all language-neutral. Our first results are promising.Comment: To appear at EACL 201

A Vehicular Traffic Flow Model Based on a Stochastic Acceleration Process

A new vehicular traffic flow model based on a stochastic jump process in vehicle acceleration and braking is introduced. It is based on a master equation for the single car probability density in space, velocity and acceleration with an additional vehicular chaos assumption and is derived via a Markovian ansatz for car pairs. This equation is analyzed using simple driver interaction models in the spatial homogeneous case. Velocity distributions in stochastic equilibrium, together with the car density dependence of their moments, i.e. mean velocity and scattering and the fundamental diagram are presented.Comment: 27 pages, 6 figure

Modelling Acceleration Decisions in Traffic Streams with Weak Lane Discipline: A Latent Leader Approach

Acceleration is an important driving manoeuvre that has been modelled for decades as a critical element of the microscopic traffic simulation tools. The state-of-the art acceleration models have however primarily focused on lane based traffic. In lane based traffic, every driver has a single distinct lead vehicle in the front and the acceleration of the driver is typically modelled as a function of the relative speed, position and/or type of the corresponding leader. On the contrary, in a traffic stream with weak lane discipline, the subject driver may have multiple vehicles in the front. The subject driver is therefore subjected to multiple sources of stimulus for acceleration and reacts to the stimulus from the governing leader. However, only the applied accelerations are observed in the trajectory data, and the governing leader is unobserved or latent. The state-of-the-art models therefore cannot be directly applied to traffic streams with weak lane discipline. This prompts the current research where we present a latent leader acceleration model. The model has two components: a random utility based dynamic class membership model (latent leader component) and a class-specific acceleration model (acceleration component). The parameters of the model have been calibrated using detailed trajectory data collected from Dhaka, Bangladesh. Results indicate that the probability of a given front vehicle of being the governing leader can depend on the type of the lead vehicle and the extent of lateral overlap with the subject driver. The estimation results are compared against a simpler acceleration model (where the leader is determined deterministically) and a significant improvement in the goodness-of-fit is observed. The proposed models, when implemented in microscopic traffic simulation tools, are expected to result more realistic representation of traffic streams with weak lane discipline

The Annotators Did Not Agree on Some of the Guidelines Examples

International audienceWe propose the annotation of 7 sentences out of the 31 provided in the ISA-17 shared task, according to our understanding of the guidelines. We include here several remarks to improve the annotation and provide some tools to make the task easier