Conjecturing and Proving in Dynamic Geometry: the Elaboration of Some Research Hypotheses

Research has shown that the tools provided by dynamic geometry systems impact students’ approach to investigating open problems in Euclidean geometry. We particularly focus on types of processes that might be induced by certain uses of tools available in Cabri. Building on the work of Arzarello (Arzarello et al., 1998) and Olivero (1999, 2002), we have conceived a model describing some cognitive processes that may occur during the production of conjectures and proofs in a dynamic geometry environment and that might be related to the use of specific dragging schemes. Moreover, we hypothesize that such cognitive processes could be induced by introducing students to the use of dragging schemes

Image-processing assisted characterization of spray injection systems

The objective of this work is to investigate the spray characteristics of a fuel injection nozzle. The analysis is performed by means of a framework which exploits different image processing techniques to provide spray-related data to the operator. Innovative metrics are introduced to increase the accuracy and efficiency of the scheme. Experimental results show that it is possible to automatically get useful information about the spray distribution, asymmetries and key properties together with the capability to measure significant angles and other information to detect anomalies in the injection system

A drone-based image processing system for car detection in a smart transport infrastructure

In this paper we present a car detection system prototyped within an experimental project. It analyzes video streams recorded by drones flying over an urban environment. The intended final goal is the automatic provision of helpful information, such as the available parking spaces and the level of congestion of the streets. The system has been tested both in a desktop PC and on an embedded system. The experimental results show a significant accuracy and prove the feasibility of novel on-board services

A sensor aided H.264 encoder tested on aerial imagery for SFM

Email Print Request Permissions Standard video coding systems currently employed in UAV (Unmanned Aerial Vehicle) and aerial drone applications do not rely on some peculiarities in terms of scene 3D model and correlation among successive frames. In particular, the observed scene is static, i.e. the camera movement is dominant, and it can often be well approximated with a plane. Moreover, camera position and orientation can be obtained from the navigation system. Therefore, correspondent points on two video frames are linked by a simple homography. This paper presents novel results obtained by a low-complexity sensor aided H.264 encoder, recently developed at CIRA and yet tested on simulated data. The proposed encoder employs a new motion estimation scheme which make use of the global motion information provided by the onboard navigation system. The homography is used in order to initialize the block matching algorithm allowing a more robust motion estimation and a smaller search window, and hence reducing the complexity. The tests are made coding real aerial imagery, captured to be used for 3D scene reconstruction. The images are acquired by an high resolution camera mounted on a small drone, flying at low altitude

H.264 sensor aided video encoder for UAV BLOS missions

This paper presents a new low-complexity H.264 encoder, based on x264 implementation, for Unmanned Aerial Vehicles (UAV) applications. The encoder employs a new motion estimation scheme which make use of the global motion information provided by the onboard navigation system. The results are relevant in low frame rate video coding, which is a typical scenario in UAV behind line-of-sight (BLOS) missions

Storage of poisonous substances and firearms in homes with young children visitors and older adults

Most unintentional childhood poisonings and firearm injuries occur in residential environments. Therefore, a preventive strategy includes limiting children’s access to poisons and firearms through safe storage. This study examines storage of poisons and firearms among households with older adults, and households where young children reside compared to those where they visit only

Estimation of taurindicine hybridization of American Zebu cattle in Brazil

Our objective was to estimate Bos primigenius taurus introgression in American Zebu cattle. One hundred and four American Zebu (Nellore) cattle were submitted to mtDNA, microsatellite and satellite analysis. Twenty-three alleles were detected in microsatellite analysis, averaging 4.6 +/- 1.82/locus. Variance component comparisons of microsatellite allele sizes allowed the construction of two clusters separating taurus and indicus. No significant variation was observed when indicus and taurus mtDNA were compared. Three possible genotypes of 1711b satellite DNA were identified. All European animals showed the same restriction pattern, suggesting a Zebu-specific restriction pattern. The frequencies of B. primigenius indicus-specific microsatellite alleles and 1711b satellite DNA restriction patterns lead to an estimate of 14% taurine contribution in purebred Nellore.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP