Rio de Janeiro State University

About: Rio de Janeiro State University is a education organization based out in Rio de Janeiro, Brazil. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 16631 authors who have published 30919 publications receiving 465753 citations. The organization is also known as: UERJ & Rio de Janeiro State University.

Review of methodologies and tasks in swarm robotics towards standardization

Abstract: Swarm Robotics (SR) is an extension of the study of Multi-Robot Systems that exploits concepts of communication, coordination and collaboration among a large number of robots. The massive parallelization yielded by the robots working together can make a task faster than in the case of the usage of a single complex robot. One of the main aspects in robotic swarms is that the control is decentralized by definition and distributed among the robots of the swarm, improving the system robustness and fault-tolerance. Furthermore, this characteristic often allows the emergence of collective behaviors from the robot's interaction with each other and with the environment through their embodied sensors and actuators. In most cases, the number of inputs from sensor readings turns analytical solutions hard or even impossible. Thus, many ad-hoc approaches are contributed to deal with the situation at hand. The main goal of this review is to find out, through the study of existing research works of the field, the reason behind the lack of exploitation of swarm robotic systems in real-world applications. For this purpose, we first review the different possibilities of study in SR: physical and simulated robotic platforms, development methodologies and the variety of basic tasks and collective behaviors. We then briefly describe some fields related do SR that have a big impact on the development of SR. After that, based on existing taxonomies found in literature, we categorize existing research works regarding SR in two large main groups: those that deal with SR design and those that deal with tasks as required in SR. The review of both existing robots and techniques in the literature show a diversity of approaches to discuss SR issues. Nonetheless, it is easily noticeable from these works that there is a clamant absence of solid real-world applications of SR. An analysis of the interests and bottlenecks of this field indicates that the number of research works is smaller than those in other related areas. This suggests that, even though with many research studies, the field of SR is not yet mature enough, mainly due the absence of a universal methodology and generic robots that can be used in any, or at least in many, applications. Thus, we emphasize, discuss and analyze the urgent need for standardization of many aspects in SR, including hardware and software, as to allow a possible flourishing of SR applicability to real-world applications. This standardization could accelerate a great deal the field of SR, thus facilitating the development of SR solutions for applications that impact our daily life.

Spatial and temporal organization of aquatic insects assemblages in the longitudinal gradient of a tropical river

Abstract: The distribution and abundance of aquatic insects were studied in the longitudinal gradient of the watershed of Macae River, a coastal Atlantic Forest river in South-eastern Brazil. Sampling stations were selected in the first, second, fourth, fifth, and sixth orders and sampled in April, July, and October 1995. This represented the end of the rainy season, the dry season, and the beginning of another rainy season, respectively. In each month four samples were collected using a Surber sampler from each of the following substrates: sand, litter deposited in pool areas, litter in riffle areas, and stones. A total of 46,431 specimens of aquatic insects belonging to ten orders were obtained. The data were analyzed by the multivariate methodologies of Correspondence Analysis (CA) and Cluster Analysis (UPGMA) using the similarity index of Morisita, for all three months. Both showed a significant faunal disrupture in the river, which can be divided in two sections: the upper one, from first to fourth orders, and the lower section, including fifth and sixth orders. The same results were obtained with presence-absence matrices, using Jaccard similarity index, showing that the changes are not only due to quantitative differences. A Mantel test was used to compare the assemblage composition temporally and no difference was detected between the three months. Moreover, a Canonical Correspondence Analysis (CCA) was applied to the data to check which of the 14 physical and chemical variables significantly explained macroinvertebrate community variation. The most significant variables were conductivity, CPOM, and pH for the upper stations (1st, 2nd and 4th orders), and alkalinity, FPOM, and HCO3 for the lower stations (5th and 6th orders).

Comparison between the abuse assessment screen and the revised conflict tactics scales for measuring physical violence during pregnancy

Abstract: Study objective: Because of the promise of its ability to quickly identify cases of violence against women during pregnancy, the abuse assessment screen (AAS) should be the focus of numerous psychometric evaluations. This paper assesses its measurement accuracy compared with the revised conflict tactics scales (CTS2) used as standard. Design: Cross sectional study. Besides several ancillary questions, the AAS consists of three anchor questions about violence against pregnant women. These are inclusive, respectively covering lifetime, preceding 12 months, and pregnancy periods. These questions are the main focus of this article. The CTS2 physical aggression scale consists of 12 items divided into minor and severe subscales. A positive event is defined as having at least one positive item in the respective subscale. The 12 item score is also used. Setting and participants: The instruments were applied to 748 women, 24 to 72 hours after delivery in three major public sector maternity wards of Rio de Janeiro from March to September 2000. Main results: According to the CTS2, prevalences of minor and severe physical violence perpetrated against a pregnant woman are 18.4% (95% CI 15.7 to 21.4) and 7.6% (95% CI 5.8 to 9.8), respectively. Taking these subscales as standards, sensitivities are 31.9% (95% CI 24.9 to 40.3) and 61.4% (95% CI 47.6 to 74.0), respectively. Specificities are above 97%. Conclusion: These findings are somewhat worrying because the number of victims who are not identified and offered assistance is considerable. On a practical note, it would be sensible not to use the AAS as a stand alone screening tool until more evidence is gathered.

The significance of leaf water repellency in ecohydrological research: a review

Abstract: Numerous studies in materials science and chemistry have expanded our understanding of the repellency of water droplets from surfaces. Much of the inspiration for the development of synthetic water-repellent materials came from the examination of water-repellent properties of animals and plants in the natural environment. The hydrological significance of water repellency in the natural environment remains an underexplored research topic. Although the hydrological significance of soil water repellency has become well established in the ecohydrology and water resources literature, fewer studies have examined the significance of leaf water repellency. This review examines the properties of leaf water repellency, the methodologies used to calculate leaf water repellency, the leaf surface properties that promote leaf water repellency, and the significance of leaf water repellency in ecohydrological research. The repellency of a water droplet by a leaf surface is functionally important among plant species and may reflect selective strategies that either favour leaf water uptake in drought-prone environments or promote higher photosynthetic efficiency during prolonged periods of precipitation through higher repellency. Information on the functional significance of leaf water repellency in hydrologic models could enhance our understanding of the delivery of water resources to municipal reservoirs and fill in a missing gap in our understanding of leaf water repellency as a process that influences discharge, and by extension, water resources. Copyright © 2012 John Wiley & Sons, Ltd.

Search for pair production of first- and second-generation scalar leptoquarks in pp collisions at √s=7TeV

Abstract: Results are presented from a search for the pair production of first- and second-generation scalar leptoquarks in proton-proton collisions at sqrt(s)= 7 TeV. The data sample corresponds to an integrated luminosity of 5.0 inverse femtobarns, collected by the CMS detector at the LHC. The search signatures involve either two charged leptons of the same-flavour (electrons or muons) and at least two jets, or a single charged lepton (electron or muon), missing transverse energy, and at least two jets. If the branching fraction of the leptoquark decay into a charged lepton and a quark is assumed to be beta=1, leptoquark pair production is excluded at the 95% confidence level for masses below 830 GeV and 840 GeV for the first and second generations, respectively. For beta = 0.5, masses below 640 GeV and 650 GeV are excluded. These limits are the most stringent to date.