Private Provision of Water Service in Brazil: Impacts on Access and Affordability

Brazil has been experimenting with Private Sector Participation (PSP) in the water and sanitation sector in various forms since the mid-nineties, one of the most common being concession contracts. Currently, 25% of the population is served by companies with private sector participation and this figure could grow to 36% within 10 years. This paper studies past and ongoing experiences with private provision of water services in Brazil and assesses their impact on access and affordability indicators. It also discusses the social policies in place to improve those indicators, especially those targeting the poor. It uses different estimation methods and datasets to determine whether or not there is any difference in access to water supply and ability to pay water bills between municipalities that opted to entrust the provision of water services with private operators and those that kept them public. Moreover, whenever possible, the analysis is broken down by income (GDP) deciles in an attempt to evaluate the impact of private provision on lower income families. The results obtained entail the conclusion that PSP in Brazil has delivered higher access to water services, benefiting mostly the poor. They are inconclusive regarding affordability of water services though.Water services, access, affordability, panel data, private sector participation

A Flexible Implementation of a Matrix Laurent Series-Based 16-Point Fast Fourier and Hartley Transforms

This paper describes a flexible architecture for implementing a new fast computation of the discrete Fourier and Hartley transforms, which is based on a matrix Laurent series. The device calculates the transforms based on a single bit selection operator. The hardware structure and synthesis are presented, which handled a 16-point fast transform in 65 nsec, with a Xilinx SPARTAN 3E device.Comment: 4 pages, 4 figures. IEEE VI Southern Programmable Logic Conference 201

Visual perception for basketball shooting

Vision is one of the six sensory systems that we use to know and interact with our environment but has been singled out as the most important form of exteroception for motor control. The reason for this implicit upgrade is probably that many human actions are directed at objects or targets beyond our immediate physical contact. The only link between these objects and us is the pattern of light reflected from their surfaces, and yet we identify and act upon them with great ease. No doubt humans make significant strides in establishing appropriate relations between perceptions and actions at early stages of their development. When my nephew Rodrigo was three months old it took him considerable perseverance and a lot of jerky movements to finally grasp the toy my mother was patiently holding and rambling. But once the relations between perceptions and actions are better established, humans can be incredibly skilful at interacting with distant objects even when the constraints imposed on the interaction are severe and a high degree of precision is required. Like many other sportive tasks, basketball shooting is characterised by tight temporal constraints, limited spatial variation, and high accuracy demands. How basketball players manage to consistently throw a ball through the basket, even if severely challenged by their opponents, is a remarkable feat that has occupied scientists for years, and the present work is but another step in understanding the intricate relations between visual perception and action in such a context where few errors are allowed and few are made. The research reported in the present thesis was conducted to uncover the visual basis of basketball shooting. Basketball shooting consists of throwing a ball on a parabolic flight that passes through a metal rim twice the size of the ball at three metres height. Common shooting types are the free throw and the jump shot. Free throws are taken in less than 10 s from the 4.6 m line without opposition. Jump shots can be taken from anywhere in the field, usually in the presence of opponents, and imply that the ball is released while the player is airborne. Conventional knowledge stipulates that players must see the basket before they shoot. Straightforward as this statement may seem, it can be incorrect in two ways. First, it is not granted that vision is required before the shot, as opposed to during the shot. While vision gathered before the movement may be useful, it may also be insufficient or unnecessary for accurate shooting. This temporal aspect is relevant because it gives insight into the timely interaction between visual perception and action. Second, it is not certain that the player must actually see the basket, as opposed to merely looking at it. The location of the target may be perceived through various information sources, not necessarily retinal ones. This spatial aspect is relevant because it gives insight into the optical basis of goal-directed movement. In what follows we describe in more detail what these temporal and spatial aspects of visual perception andaction consist of, backed up with relevant literature. Next, we briefly review the available literature on the visual perception of basketball shooting and introduce six experiments in which the temporal and spatial aspects of basketball shooting are investigated

Visual perception in dynamic far aiming

Vision is one of the six sensory systems that we use to know and interact with our environment but it has been singled out as the most important form of exteroception for guiding action. The reason for this is probably that many human actions are directed at objects or targets beyond our immediate physical contact. The only link between these objects and us is the pattern of light reflected from their surfaces, and yet we identify and act upon them with great ease. No doubt, humans make significant strides in establishing appropriate relations between perceptions and actions at early stages of development. (Just think of the time and practice it takes a baby to be able to grasp an object within their reach.) But once the relations between perceptions and actions are better established, humans can be incredibly skillful at interacting with distant objects even when the constraints imposed on the interaction are severe and a high degree of precision is required. In sports, there is an abundance of far aiming tasks, often with the purpose of scoring. Although it is evident that vision plays an important role in guiding far aiming actions, its exact role is often unclear. For example in static far aiming tasks such as rifle shooting, free throw shooting or billiards, the duration of the final fixation on the target before initiating the final movements correlates with expertise. In contrast, research has shown that in tasks that are more dynamic it is not so much the fixation duration that correlates with expertise but rather the timing of that fixation. These results beg the question What role does vision play in guiding action? One researcher (Gibson, 1966) proposed that the role of vision (or other sensory organs) is to detect patterns in the ambient array through stimulation of receptors. This detection of specific patterns leads to the perception of information that can guide actions. At the time, this was a radical theory because it proposed that perception was direct, or unmediated by cognitive processes, and it also highlighted the role of action in picking up visual information. In other words, it proposed that perception guides action and that action discloses perception in a cyclical bidirectional manner. Fast-forward three decades and researchers were terribly excited by the accessibility of eye-trackers; hefty glasses sometimes mounted on helmets which could show a researcher where the wearer was looking (or to be more precise, the direction where the wearer was looking). An enormously influential piece of research by Vickers in 1996 set the scene for the following two-decades of eye-tracking studies. Two decades looking at where sportspeople were looking without too much scrutiny over what role vision plays in guiding action. Elsewhere research by the Oudejans’ group (2002, 2006, 2007, 2008) contradicted both the findings and interpretations. While Vickers found long fixations before movement initiation, Oudejans found late fixations during the movement. In this talk we will explore and critically analyse the research on visual perception in dynamic far-aiming