3 resultados para Peer-based intervention

em Digital Commons - Michigan Tech


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Anonymity systems maintain the anonymity of communicating nodes by camouflaging them, either with peer nodes generating dummy traffic or with peer nodes participating in the actual communication process. The probability of any adversary breaking down the anonymity of the communicating nodes is inversely proportional to the number of peer nodes participating in the network. Hence to maintain the anonymity of the communicating nodes, a large number of peer nodes are needed. Lack of peer availability weakens the anonymity of any large scale anonymity system. This work proposes PayOne, an incentive based scheme for promoting peer availability. PayOne aims to increase the peer availability by encouraging nodes to participate in the anonymity system by awarding them with incentives and thereby promoting the anonymity strength. Existing incentive schemes are designed for single path based approaches. There is no incentive scheme for multipath based or epidemic based anonymity systems. This work has been specifically designed for epidemic protocols and has been implemented over MuON, one of the latest entries to the area of multicasting based anonymity systems. MuON is a peer-to-peer based anonymity system which uses epidemic protocol for data dissemination. Existing incentive schemes involve paying every intermediate node that is involved in the communication between the initiator and the receiver. These schemes are not appropriate for epidemic based anonymity systems due to the incurred overhead. PayOne differs from the existing schemes because it involves paying a single intermediate node that participates in the network. The intermediate node can be any random node that participates in the communication and does not necessarily need to lie in the communication path between the initiator and the receiver. The light-weight characteristics of PayOne make it viable for large-scale epidemic based anonymity systems.

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With the number of ischemia reperfusion (I/R) injuries on the rise, and a lack of pharmacological intervention aimed at reducing free radical damage associated with I/R, we have developed 30 indole phenolic antioxidants that were synthesized by click chemistry to couple our indole with a phenolic or anisole derivative. The total antioxidant activity of the analogues was tested in vitro using the ferric thiocyanate lipid emulsion method. Compounds containing hydroxyl or methoxy aromatics at the 3 or 4 position on the aromatic coupled to the indole exhibited increased antioxidant scavenging. 4-methoxyindole derivatives (8a-e) exhibited increased scavenging (p < 0.05) compared to the known antioxidant butylated hydroxyanisole (BHA).

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Today’s technology is evolving at an exponential rate. Everyday technology is finding more inroads into our education system. This study seeks to determine if having access to technology, including iPad tablets and a teacher's physical science webpage resources (videos, PowerPoint® presentations, and audio podcasts), assists ninth grade high school students in attaining greater comprehension and improved scientific literacy. Comprehension of the science concepts was measured by comparing current student pretest and post test scores on a teacher-written assessment. The current student post test scores were compared with prior classes’ (2010-2011 and 2009-2010) to determine if there was a difference in outcomes between the technology interventions and traditional instruction. Students entered responses to a technology survey that measured intervention usage and their perception of helpfulness of each intervention. The current year class’ mean composite scores, between the pretest and post test increased by 6.9 points (32.5%). Student composite scores also demonstrated that the interventions were successful in helping a majority of students (64.7%) attain the curriculum goals. The interventions were also successful in increasing student scientific literacy by meeting all of Bloom's cognitive levels that were assessed. When compared with prior 2010-2011 and 2009-2010 classes, the current class received a higher mean post test score indicating a positive effect of the use of technological interventions. The survey showed a majority of students utilized at least some of the technology interventions and perceived them as helpful, especially the videos and PowerPoint® presentations.