Online Discrete Anchor Graph Hashing for Mobile Person Re-Identification

With the advance of mobile technologies, mobile devices such as unmanned aerial vehicle (UAV) become more important in video surveillance. By applying mobile person re-identification (re-id), mobile devices can monitor pedestrians in the transportation system from complex environments. Since the computing and storage resources of mobile devices are limited, traditional person re-id methods are not appropriate for mobile condition. Besides, mobile person re-id task also requires real-time processing. In this paper, we propose a novel hashing method: online discrete anchor graph hashing (ODAGH) for mobile person re-id. ODAGH integrates the advantages of online learning and hashing technology. In ODAGH, we propose an online discrete optimization algorithm to improve the efficiency of anchor graph learning in the online scenario. Experimental results demonstrate the superiority of ODAGH in terms of both effect and efficiency.

A Compact Road Weather Station

Road Weather Stations (RWS) have been extensively used for collecting information about slippery road conditions during the last thirty years. Recently, vehicle based mobile road condition monitors have challenged the fixed RWS. Both approaches have their advantages and can complete each other. Fixed RWS can provide accurate trend data whereas mobile condition monitors can cover the road sections between RWS. Nevertheless, a traditional RWS is a fairly expensive investment, typically 30 000 € or much more, and often includes a number of components not essential for the purpose of measuring and predicting road conditions. To reduce the total cost we have developed a bare minimum of a fixed RWS including only the essential sensor information like road surface state, friction, water and frozen layer thickness, air temperature, road surface temperature, dew point temperature, atmospheric pressure, wind speed and estimated ground temperature at -6 cm. The targeted end user price of the station is one third of the traditional price level. We report experiences with the first installations during 2020-2021.

Effects of screen-responsive visualization on data comprehension

Visualization interfaces designed for heterogeneous devices such as wall displays and mobile screens must be responsive to varying display dimensions, resolution, and interaction capabilities. In this paper, we report on two user studies of visual representations for large versus small displays. The goal of our experiments was to investigate differences between a large vertical display and a mobile hand-held display in terms of the data comprehension and the quality of resulting insights. To this end, we developed a visual interface with a coordinated multiple view layout for the large display and two alternative designs of the same interface – a space-saving boundary visualization layout and an overview layout – for the mobile condition. The first experiment was a controlled laboratory study designed to evaluate the effect of display size on the perception of changes in a visual representation, and yielded significant correctness differences even while completion time remained similar. The second evaluation was a qualitative study in a practical setting and showed that participants were able to easily associate and work with the responsive visualizations. Based on the results, we conclude the paper by providing new guidelines for screen-responsive visualization interfaces.

Ethane measurement by Picarro CRDS G2201-i in laboratory and field conditions: potential and limitations

Ethane can be used as a tracer gas to distinguish methane sources, both at the local and global scale. Currently, ethane can be successfully measured using flasks or dedicated in-situ analyzers. In our study, we consider the possibility of using the CRDS Picarro G2201-i instrument, dedicated to isotopic CH4 and CO2, for suitable measurements of ethane:methane ratio in mobile field, near-source conditions. Our work was divided into three steps. First, laboratory tests were run to characterize the instrument in stationary conditions. Then the instrument performance was tested in the field, as part of a controlled release experiment and finally during mobile measurements focused on gas compressor stations. The results from the field are compared with the results from other instruments, dedicated to ethane measurements. Our study clearly shows the potential of using the CRDS G2201-i instrument to determine the ethane:methane ratio in methane plumes in mobile condition with an ethane uncertainty of 50 ppb. Assuming typical ethane to methane ratio ranging between 0 and 0.1 ppb ppb−1 we conclude that the instrument can correctly estimate the “true” ethane to methane ratio within 1-sigma uncertainty in CH4 enhancements of 1 ppm or more as can be found in the vicinity of strongly emitting sites (such as natural gas compressor station).