Marker based Thermal-Inertial Localization for Aerial Robots in Obscurant Filled Environments

For robotic inspection tasks in known environments fiducial markers provide a reliable and low-cost solution for robot localization. However, detection of such markers relies on the quality of RGB camera data, which degrades significantly in the presence of visual obscurants such as fog and smoke. The ability to navigate known environments in the presence of obscurants can be critical for inspection tasks especially, in the aftermath of a disaster. Addressing such a scenario, this work proposes a method for the design of fiducial markers to be used with thermal cameras for the pose estimation of aerial robots. Our low cost markers are designed to work in the long wave infrared spectrum, which is not affected by the presence of obscurants, and can be affixed to any object that has measurable temperature difference with respect to its surroundings. Furthermore, the estimated pose from the fiducial markers is fused with inertial measurements in an extended Kalman filter to remove high frequency noise and error present in the fiducial pose estimates. The proposed markers and the pose estimation method are experimentally evaluated in an obscurant filled environment using an aerial robot carrying a thermal camera.Comment: 10 pages, 5 figures, Published in International Symposium on Visual Computing 201

Early Identification of Violent Criminal Gang Members

Gang violence is a major problem in the United States accounting for a large fraction of homicides and other violent crime. In this paper, we study the problem of early identification of violent gang members. Our approach relies on modified centrality measures that take into account additional data of the individuals in the social network of co-arrestees which together with other arrest metadata provide a rich set of features for a classification algorithm. We show our approach obtains high precision and recall (0.89 and 0.78 respectively) in the case where the entire network is known and out-performs current approaches used by law-enforcement to the problem in the case where the network is discovered overtime by virtue of new arrests - mimicking real-world law-enforcement operations. Operational issues are also discussed as we are preparing to leverage this method in an operational environment.Comment: SIGKDD 201

First record of Capparimyia savastani in Greece

Κατά τη διάρκεια του θέρους του έτους 2008 παρατηρήθηκε εκτεταμένη προσβολή σε ανθοφόρους οφθαλμούς φυτών κάπαρης (Capparis sp.) στο νησί της Μήλου. Από ενήλικα άτομα που προήλθαν από δείγματα προσβεβλημένων φυτών διαπιστώθηκε ότι πρόκειται για το είδος Capparimyia savastani (Martelli) (Diptera: Tephritidae). Η παρουσία του εντόμου αυτού καταγράφεται για πρώτη φορά στην Ελλάδα. Το έντομο αυτό προβάλλει τους ανθοφόρους οφθαλμούς φυτών που ανήκουν στο γένος Capparis και φαίνεται ότι μπορεί να προκαλέσει εκτεταμένες ζημιές σε καλλιεργούμενα και αυτοφυή φυτά κάπαρης.During the summer of 2008 extensive infestation was observed on edible flower buds of wild and cultivated caper plants (Capparis sp.) in Milos island. Larvae were taken from infested plants and kept in laboratory conditions at 24±1oC, 70±5% RH, and under a photoperiod of 16:8 (L:D) h until adult’s emergence. Adults were identified as the species Capparimyia savastani (Martelli) (Diptera: Tephritidae). The presence of this species is recorded for the first time in Greece. The larvae of C. savastani fed on flower buds of caper plants and it appears to be capable to cause extensive damage on cultivated and wild caper

First record of Capparimyia savastani in Greece

Κατά τη διάρκεια του θέρους του έτους 2008 παρατηρήθηκε εκτεταμένη προσβολή σε ανθοφόρους οφθαλμούς φυτών κάπαρης (Capparis sp.) στο νησί της Μήλου. Από ενήλικα άτομα που προήλθαν από δείγματα προσβεβλημένων φυτών διαπιστώθηκε ότι πρόκειται για το είδος Capparimyia savastani (Martelli) (Diptera: Tephritidae). Η παρουσία του εντόμου αυτού καταγράφεται για πρώτη φορά στην Ελλάδα. Το έντομο αυτό προβάλλει τους ανθοφόρους οφθαλμούς φυτών που ανήκουν στο γένος Capparis και φαίνεται ότι μπορεί να προκαλέσει εκτεταμένες ζημιές σε καλλιεργούμενα και αυτοφυή φυτά κάπαρης.During the summer of 2008 extensive infestation was observed on edible flower buds of wild and cultivated caper plants (Capparis sp.) in Milos island. Larvae were taken from infested plants and kept in laboratory conditions at 24±1oC, 70±5% RH, and under a photoperiod of 16:8 (L:D) h until adult’s emergence. Adults were identified as the species Capparimyia savastani (Martelli) (Diptera: Tephritidae). The presence of this species is recorded for the first time in Greece. The larvae of C. savastani fed on flower buds of caper plants and it appears to be capable to cause extensive damage on cultivated and wild caper

Bridging the Gap: the need for a systems thinking approach in understanding and addressing energy and environmental performance in buildings

Innovations in materials, construction techniques and technologies in building construction and refurbishment aim to reduce carbon emissions and produce low-energy buildings. However, in-use performance consistently misses design specifications, particularly those of operational energy use and indoor environmental quality. This performance gap risks reducing design, technology, sustainability, economic, health and well-being benefits. In this paper, we compare settings of the Chinese and the UK buildings sectors and relate their historical context, design, construction and operation issues impacting energy performance, indoor environmental quality, occupant health and well-being. We identify a series of key, common factors of ‘total’ building performance across these two settings: the application of building regulations, the balance between building cost and performance, skills, construction and operation. The dynamic and complex interactions of these factors are currently poorly understood and lead to building performance gaps. We contend that a systems approach in the development of suitable building assessment methods, technologies and tools could enable the formulation and implementation of more effective policies, regulations and practices. The paper illustrates the application of the approach to the UK and Chinese settings. A full application of a systems approach may help to provide a more dynamic understanding of how factor interactions impact the ‘total’ building performance gaps and help address its multiple causes

Host plant range of a fruit fly community (Diptera: Tephritidae): Does fruit composition influence larval performance?

Background: Phytophagous insects differ in their degree of specialisation on host plants, and range from strictly monophagous species that can develop on only one host plant to extremely polyphagous species that can develop on hundreds of plant species in many families. Nutritional compounds in host fruits affect several larval traits that may be related to adult fitness. In this study, we determined the relationship between fruit nutrient composition and the degree of host specialisation of seven of the eight tephritid species present in La Réunion; these species are known to have very different host ranges in natura. In the laboratory, larval survival, larval developmental time, and pupal weight were assessed on 22 fruit species occurring in La Réunion. In addition, data on fruit nutritional composition were obtained from existing databases. Results: For each tephritid, the three larval traits were significantly affected by fruit species and the effects of fruits on larval traits differed among tephritids. As expected, the polyphagous species Bactrocera zonata, Ceratitis catoirii, C. rosa, and C. capitata were able to survive on a larger range of fruits than the oligophagous species Zeugodacus cucurbitae, Dacus demmerezi, and Neoceratitis cyanescens. Pupal weight was positively correlated with larval survival and was negatively correlated with developmental time for polyphagous species. Canonical correspondence analysis of the relationship between fruit nutrient composition and tephritid survival showed that polyphagous species survived better than oligophagous ones in fruits containing higher concentrations of carbohydrate, fibre, and lipid. Conclusion: Nutrient composition of host fruit at least partly explains the suitability of host fruits for larvae. Completed with female preferences experiments these results will increase our understanding of factors affecting tephritid host range. (Résumé d'auteur