Quality of Floating Car Data

Meanwhile, Floating Car Data (FCD) is a widely available and affordable data source for traffic surveillance. The German Aerospace Center, Institute of Transportation Systems (DLR-TS) receives FCD from taxi-fleets ranging from 300 to 4000 vehicles from various German and European cities since the year 2002. To extract common traffic variables like travel times or travel speeds and generate traffic information out of it, the raw GPS data of the vehicles are matched to a digital road network. However, compared to data from inductive loops, where each vehicle passing a loop generates data and the whole traffic flow is covered, the FCD represent only singular measurements. Thus, they are very noisy (especially when passing signalized intersections) and typically need to be aggregated to yield useful information. This means, a single delivered value is not very reliable and does not necessarily represent the state of the traffic flow on the according street segment. Data from some vehicles have to be aggregated and smoothed for some time interval and/or space to obtain reliable traffic information

Analysis of Berlin's taxi services by exploring GPS traces

With current on-board GPS devices a lot of data is being collected while operating taxis. This paper focuses on analysing travel behaviour and vehicle supply of the Berlin taxi market using floating car data (FCD) for one week each in 2013 and 2014. The data suggests that there is generally a demand peak on workday mornings and a second peak over a longer time in the afternoon. On weekends, the demand peaks shift towards the night. On the supply side, drivers seem to adapt to the demand peaks very efficiently, with fewer taxis being available at times of low demand, such as during midday. A spatial analysis shows that most taxi trips take place either within the city centre or from/to Tegel Airport, the city's largest single origin and destination. Drivers spend a large amount of their work time on waiting for customers and the taxi rank at Tegel Airport is the most popular one

THE MECHANISMS AND ROLES OF POST-TRANSLATIONAL PROCESSING OF THE DROSOPHILA FIBROBLAST GROWTH FACTOR BRANCHLESS DURING DEVELOPMENT

During embryonic development, cells communicate with each other to cooperate to form organized tissues. Cells spatiotemporally coordinate with each other by communicating with signaling proteins such as Fibroblast Growth Factor (FGF) that travel from source to target cells to activate various functions. To better understand cell communication during tissue morphogenesis, this study aimed to address a fundamental question: how different cellular and molecular mechanisms in signal-producing cells prepare and release signals at the correct time and location and at an appropriate level. This research focuses on the intercellular communication of the Drosophila FGF Branchless (Bnl) to elucidate this question. Bnl is dynamically produced in restricted groups of cells to induce morphogenesis of tracheal airway epithelial tubes. Tracheal cells receive the signal over distance by extending long receptor-containing filopodia, or cytonemes, to dynamically contact the Bnl-source. This work discovered two post-translational modifications of Bnl that regulate its polarized intracellular trafficking and cytoneme-mediated intercellular dispersal. During intracellular trafficking through the source cell Golgi network, Bnl is endo-proteolytically cleaved at a single site by the protease Furin-1. This cleavage activates polarized intracellular trafficking of the truncated signal exclusively to the surface of the source cells that faces the recipient tracheal cells. Thus, the intracellular cleavage acts as a switch to catalyze the efficient trafficking of the signal to the correct location from where cytonemes can subsequently receive it. Secondly, in the endoplasmic reticulum of source cells, Bnl is modified with a glycosylphosphatidylinositol (GPI) moiety at its C-terminus. This lipid moiety tethers Bnl molecules to the outer leaflet of the cell membrane, inhibiting its free release and ensuring signal exchange solely by direct physical contacts established by cytonemes. Therefore, this study discovered how Bnl is prepared by the source cells to ensure its subsequent target-specific intercellular dispersion through cytonemes. Conserved FGF family proteins are essential for regulating a broad spectrum of biological functions and defects in spatiotemporal levels of FGF signaling leads to severe diseases. Given the conservation of developmental signaling mechanisms in all organisms, the discovery of new regulatory mechanisms of FGF signaling has fundamental implications for understanding development and disease in humans

Biochemical and Genetic Studies of UBR3, a Ubiquitin Ligase with a Function in Olfactory and Other Sensory Systems

Our previous work identified E3 ubiquitin ligases, termed UBR1-UBR7, that contain the ~70-residue UBR box, a motif important for the targeting of N-end rule substrates. In this pathway, specific N-terminal residues of substrates are recognized as degradation signals by UBR box-containing E3s that include UBR1, UBR2, UBR4, and UBR5. The other E3s of this set, UBR3, UBR6, and UBR7, remained uncharacterized. Here we describe the cloning and analyses of mouse UBR3. The similarities of UBR3 to the UBR1 and UBR2 E3s of the N-end rule pathway include the RING and UBR domains. We show that HR6A and HR6B, the E2 enzymes that bind to UBR1 and UBR2, also interact with UBR3. However, in contrast to UBR1 and UBR2, UBR3 does not recognize N-end rule substrates. We also constructed UBR3-lacking mouse strains. In the 129SvImJ background, UBR3-/- mice died during embryogenesis, whereas the C57BL/6 background UBR3-/- mice exhibited neonatal lethality and suckling impairment that could be partially rescued by litter size reduction. The adult UBR3-/- mice had female-specific behavioral anosmia. Cells of the olfactory pathway were found to express beta-galactosidase (LacZ) that marked the deletion/disruption UBR3- allele. The UBR3-specific LacZ expression was also prominent in cells of the touch, vision, hearing, and taste systems, suggesting a regulatory role of UBR3 in sensory pathways, including olfaction. By analogy with functions of the UBR domain in the N-end rule pathway, we propose that the UBR box of UBR3 may recognize small compounds that modulate the targeting, by this E3, of its currently unknown substrates

Experiences Building an Environment friendly its in the City of Huainan

Huainan is a former mining city with about 3 million inhabitants which means in China a classification as a "third-tier" city. In this class of city are more than 200 other cities in China, which shows the great potential that Huainan has to act as a pioneer and possible blueprint for other cities. During the application phase, the progressive ideas of the city government led to experts from DLR being invited to integrate sustainable and environmental protection aspects into the project, subsumed in the "German Innovation Package". The project to set up the new ITS was planned for 2 years (2018-2020) plus a phase of 3 years for maintenance which was also used for optimization and enhancements. This contribution describes the main results und experiences of the overall project and new core functionalities of the integrated modules developed by DLR, namely a traffic and environment dashboard and weekly/monthly reports about the ITS situation, all integrated in the established web-portal KeepMoving

Utilizing historical and current travel times based on floating car data for management of an express truck fleet

During the last nine years, a couple of prototype ITS applications based on Floating Car Data (FCD) of taxi fleets have been developed at German Aerospace Center (DLR). A core application is a route guidance and monitoring system based on current and historical road segment travel times. Recently, it has been extended for use in the German funded project SmartTruck, run by a consortium consisting of the logistics key player DHL, DLR and the German Research Center for Artificial Intelligence (DFKI). An important aim of the project was the use of historical and current traffic information for energy-efficient, optimized offline planning and dynamic re-planning of the tours of DHL express trucks in Berlin, Germany. This paper discusses the architecture of the SmartTruck system and the methodology used to generate historic and current road segment travel times from positional data

Traffic Information Systems for Smart Mobility as part of Smart Cities

The unlimited and unrestricted mobility of people and goods in urban areas is one of the key factors for economic and social development of the city. Today with the availability of smart technologies and various intelligent transportation and telematics solutions the Smart Mobility as part of a Smart City is possible to maintain the mobility ecosystem in the city. But to make the urban mobility smart by assuring the sustainability, safety, low emission and comfort in urban transport new mobility concepts are required. This paper introduces an architecture for smart mobility systems and describes in general the requirements of such systems. The focus for this contribution is on the traffic information and management systems for public, private and shared mobility. In addition to the traffic information and data sources, this paper also deals with social media as new traffic data source as well as the environment data. Furthermore, some use cases selected from different national and international ITS projects are also presented

Short Term Travel Time Prediction Using Floating Car Data Based On Cluster Analysis

Precise short-term prediction of traffic parameters such as flow and travel-time is a necessary component for many ITS applications. This work describes the research on a novel, fast, and robust algorithm which is based on a partitioning cluster analysis. It is able to calculate travel times from Floating Car Data (FCD) for a whole city, even for minor roads. A potential problem with FCD is the insufficient penetration rate of smaller taxi fleets and the resulting noisy and/or missing data (4). The new approach accounts for this by smoothing the data by a local fit method based on polynomials with the help of a Singular Value Decomposition (SVD). Numerical experiments confirm the high efficiency of the algorithm and a promising quality of the prediction

Project drive test – comparison of five Personal Navigation Devices (PND)

This document describes the results of a measurement campaign, where five different PND’s had been compared. The comparison looked for the ability of the PND’s to compute and guide a driver on the fastest path to his or her destination. The basic performance metric which had been used to compare the five PND’s is the relative travel time gain: for each valid trip performed, there was one PND which performed worst (the vehicle guided by this PND had the longest travel time). The difference between the travel time of the worst and the PND currently looked at is the (raw) travel time gain of this PND

Fundamental diagram of traffic flows on urban roads – local versus whole-link approaches

Fundamental diagrams of traffic flow variables have been quite useful in determining freeway operations quality. However, they are usually not used for that purpose on urban roads. This work is an approach towards utilizing the fundamental diagram on urban roads, too. Based on a host of empirical as well as simulation work, the first steps towards a routine application of the fundamental diagram are sketched. In addition, two approaches are compared, one that uses a traditional fundamental diagram as measured by loop detectors, and the second one which uses a whole-link approach relating link-travel-speed with volume. Especially the travel times contain important information that can be used for traffic management applications