A transmission power self-optimization technique for wireless sensor networks

Wireless sensor networks (WSNs) are generally used to monitor hazardous events in inaccessible areas. Thus, on one hand, it is preferable to assure the adoption of the minimum transmission power in order to extend as much as possible the WSNs lifetime. On the other hand, it is crucial to guarantee that the transmitted data is correctly received by the other nodes. Thus, trading off power optimization and reliability insurance has become one of the most important concerns when dealing with modern systems based on WSN. In this context, we present a transmission power self-optimization (TPSO) technique for WSNs. The TPSO technique consists of an algorithm able to guarantee the connectivity as well as an equally high quality of service (QoS), concentrating on the WSNs efficiency (Ef), while optimizing the transmission power necessary for data communication. Thus, the main idea behind the proposed approach is to trade off WSNs Ef against energy consumption in an environment with inherent noise. Experimental results with different types of noise and electromagnetic interference (EMI) have been explored in order to demonstrate the effectiveness of the TPSO technique

Extent and Limits of the Matching Concept in Cebus Apella: A Matter of Experimental Control?

The capacity to exhibit generalized sameness-difference judgments is a hallmark of cognition that is regularly exhibited by humans. As yet, that capacity has not been well documented in New World monkeys such as the capuchin (Cebus apella). This article presents data obtained with 6 capuchin monkeys with a variety of procedures that might lead to generalized identity matching-to-sample (MTS) in this species, reporting part of a research program conducted to evaluate methods for assessing the species\u27 relational learning capacity. Our working hypothesis is that past failures to demonstrate relational learning have been caused by procedural insufficiency rather than a lack of capacity. Thus far, 6 capuchin monkeys have been tested for generalized identity MTS. The apparatus was a touchscreen-equipped microcomputer-controlled experimental chamber. Eleven sets of 3 visual stimuli (black shapes on gray backgrounds) were used. The general procedure was comprised of 4 phases: (a) simple discriminations, (b) repeated shifts of simple discriminations, (c) identity MTS training, and (d) generalized identity MTS tests. Every subject was exposed to each of the phases. Positive results on generalized identity MTS tests were obtained in all of the animals, although there have been substantial differences across individuals. The animal tested most recently has performed at levels comparable to typically developing preschool children