Drosophila Flight Stabilization Depends on Apparent Distances in Optic Flow Field

To perform daily flight tasks, insects rely heavily on their visual perception of a dynamic environment. They must process visual signals quickly and accurately and update their behavior. Flies are vulnerable to environmental disturbances, such as gusts of wind blowing them off course, but they may use the altered visual field to compensate and regain their original course. In studies using Drosophila melanogaster, it has been shown that their corrective responses can be analyzed by measuring changes in their wing beats. By enclosing a tethered fly in a cuboidal visual arena displaying a computerized optic flow field, it is possible to calculate the change in wing beat amplitudes from an infrared shadow of its wings using photodiodes and a custom wing beat analyzer. In this experiment, manipulations ofthe optic flow field are used to create a field where points have varying relative forward speed, to study how the insect performs corrective maneuvers. The results show that Drosophila have a stronger corrective response to the quickly moving, apparently near points compared to the slower moving, apparently distant points. This implies the flies are distinguishing points based on their relative speeds, inferring distance, and adjusting their corrective actions with this information.

Visual driver support system for traffic signs

It has been well documented that traffic accidents that can be avoided occur when the motorists miss or ignore traffic signs. With the attention of drivers getting diverted due to distractions like cell phone conversations, missing traffic signs has become more prevalent. Also, poor weather and other unfriendly driving conditions sometimes makes the motorists not to be alert all the time and see every traffic sign on the road. Besides, most cars do not have any form of traffic assistance. Because of heavy traffic and proliferation of traffic signs on the roads, there is a need for a system that assists the driver not to miss a traffic sign to reduce the probability of an accident. Since visual information is critical for driving, processed video signals from cameras have been chosen to assist drivers. These inexpensive cameras can be easily mounted on the automobile. The objective of the present investigation and the traffic system development is to recognize the traffic signs electronically and alert drivers. For the case study and the system development, five important and critical traffic signs have been selected. They are: STOP, NO ENTER, NO RIGHT TURN, NO LEFT TURN, and YIELD. The system was evaluated processing still pictures taken from the public roads, and the recognition results were presented in an analysis table to indicate the correct identifications and the false ones. The system reached the acceptable recognition rate of 80% for all five traffic signs. The processing rate was about three seconds. The capabilities of MATLAB, VLSI design platforms and coding have been used to generate a visual warning to complement the visual driver support system with a Field Programmable Gate Array (FPGA) on a XUP Virtex-II Pro Development System.

A visual critical ethnography of youth develoment in a Rio de Janeiro favela

Favelas are Brazilian informal housing settlements that are areas of concentrated poverty. In Rio de Janeiro, favelas are perceived as areas of heightened criminal activity and violence, and residents experience discrimination, and little access to quality education and employment opportunities. In this context, hundreds of non-formal educational arts and leisure programs work to build the self-esteem and identity of youth in Rio's favelas as a way of preventing the youth from negative local influences. The Morrinho organization, located in the Pereira da Silva favela in Rio, uses art as a way for the local male youth to communicate their lived reality. This study used a visual critical ethnographic methodology to describe the way in which the Morrinho participants interpret living in a favela. Seventeen semi-structured interviews with young men aged 15 to 29, the feature-length documentary film on the organization, 206 researcher produced documentary style photographs of the Morrinho artwork, and the researcher's field notes were analyzed. Truth claims, ways of seeing as communicated through words and actions, were induced through a cyclical process of reconstructive horizon analysis that incorporated the societal context and critical theory. The participants communicated their concerns about life in a favela; however, they did not describe their societal positions in terms of complete marginalization. They named multiple benefits of living in Pereira da Silva, discussed positive and negative experiences in school, and described ways they circumvented discrimination. Morrinho as an organization was described as an enthralling game and a social project that benefited dozens of local youth. Character development was a valuable result of participation at Morrinho. The Morrinho artwork communicates a nuanced vision of both benevolent and violent social actors, and counters the overwhelmingly negative dominant characterization of Rio de Janeiro's favelas. This study has implications for an inclusive critical pedagogy and the use of art as a means to facilitate a transformative education. Further research is recommended to explore terminology used to refer to favelas, and perceptions that favela residents have of their experiences in public education.