16,239 research outputs found
Situational Object Boundary Detection
Intuitively, the appearance of true object boundaries varies from image to
image. Hence the usual monolithic approach of training a single boundary
predictor and applying it to all images regardless of their content is bound to
be suboptimal. In this paper we therefore propose situational object boundary
detection: We first define a variety of situations and train a specialized
object boundary detector for each of them using [Dollar and Zitnick 2013]. Then
given a test image, we classify it into these situations using its context,
which we model by global image appearance. We apply the corresponding
situational object boundary detectors, and fuse them based on the
classification probabilities. In experiments on ImageNet, Microsoft COCO, and
Pascal VOC 2012 segmentation we show that our situational object boundary
detection gives significant improvements over a monolithic approach.
Additionally, our method substantially outperforms [Hariharan et al. 2011] on
semantic contour detection on their SBD dataset
Training of Crisis Mappers and Map Production from Multi-sensor Data: Vernazza Case Study (Cinque Terre National Park, Italy)
This aim of paper is to presents the development of a multidisciplinary project carried out by the cooperation between Politecnico di Torino and ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The goal of the project was the training in geospatial data acquiring and processing for students attending Architecture and Engineering Courses, in order to start up a team of "volunteer mappers". Indeed, the project is aimed to document the environmental and built heritage subject to disaster; the purpose is to improve the capabilities of the actors involved in the activities connected in geospatial data collection, integration and sharing. The proposed area for testing the training activities is the Cinque Terre National Park, registered in the World Heritage List since 1997. The area was affected by flood on the 25th of October 2011. According to other international experiences, the group is expected to be active after emergencies in order to upgrade maps, using data acquired by typical geomatic methods and techniques such as terrestrial and aerial Lidar, close-range and aerial photogrammetry, topographic and GNSS instruments etc.; or by non conventional systems and instruments such us UAV, mobile mapping etc. The ultimate goal is to implement a WebGIS platform to share all the data collected with local authorities and the Civil Protectio
Multi-sensor fire detection by fusing visual and non-visual flame features
This paper proposes a feature-based multi-sensor fire detector operating on ordinary video and long wave infrared (LWIR) thermal images. The detector automatically extracts hot objects from the thermal images by dynamic background subtraction and histogram-based segmentation. Analogously, moving objects are extracted from the ordinary video by intensity-based dynamic background subtraction. These hot and moving objects are then further analyzed using a set of flame features which focus on the distinctive geometric, temporal and spatial disorder characteristics of flame regions. By combining the probabilities of these fast retrievable visual and thermal features, we are able to detect the fire at an early stage. Experiments with video and LWIR sequences of lire and non-fire real case scenarios show good results in id indicate that multi-sensor fire analysis is very promising
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The NOMAD system : expectation-based detection and correction of errors during understanding of syntactically and semantically ill-formed text
Most large text-understanding systems have been designed under the assumption that the input text will be in reasonably "neat" form (for example, newspaper stories and other edited texts). However, a great deal of natural language text (for example, memos, messages, rough drafts, conversation transcripts, etc.) have features that differ significantly from "neat" texts, posing special problems for readers, such as misspelled words, missing words, poor syntactic construction, unclear or ambiguous interpretation, missing crucial punctuation, etc. Our solution to these problems is to make use of expectations, based both on knowledge of surface English and on world knowledge of the situation being described. These syntactic and semantic expectations can be used to figure out unknown words from context, constrain the possible word senses of words with multiple meanings (ambiguity), fill in missing words (ellipsis), and resolve referents (anaphora). This method of using expectations to aid the understanding of "scruffy" texts has bee incorporated into a working computer program called NOMAD, which understands scruffy texts in the domain of Navy ship-to-shore messages
Innovative observing strategy and orbit determination for Low Earth Orbit Space Debris
We present the results of a large scale simulation, reproducing the behavior
of a data center for the build-up and maintenance of a complete catalog of
space debris in the upper part of the low Earth orbits region (LEO). The
purpose is to determine the performances of a network of advanced optical
sensors, through the use of the newest orbit determination algorithms developed
by the Department of Mathematics of Pisa (DM). Such a network has been proposed
to ESA in the Space Situational Awareness (SSA) framework by Carlo Gavazzi
Space SpA (CGS), Istituto Nazionale di Astrofisica (INAF), DM, and Istituto di
Scienza e Tecnologie dell'Informazione (ISTI-CNR). The conclusion is that it is
possible to use a network of optical sensors to build up a catalog containing
more than 98% of the objects with perigee height between 1100 and 2000 km,
which would be observable by a reference radar system selected as comparison.
It is also possible to maintain such a catalog within the accuracy requirements
motivated by collision avoidance, and to detect catastrophic fragmentation
events. However, such results depend upon specific assumptions on the sensor
and on the software technologies
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