Delay Optimal Event Detection on Ad Hoc Wireless Sensor Networks

We consider a small extent sensor network for event detection, in which nodes take samples periodically and then contend over a {\em random access network} to transmit their measurement packets to the fusion center. We consider two procedures at the fusion center to process the measurements. The Bayesian setting is assumed; i.e., the fusion center has a prior distribution on the change time. In the first procedure, the decision algorithm at the fusion center is \emph{network-oblivious} and makes a decision only when a complete vector of measurements taken at a sampling instant is available. In the second procedure, the decision algorithm at the fusion center is \emph{network-aware} and processes measurements as they arrive, but in a time causal order. In this case, the decision statistic depends on the network delays as well, whereas in the network-oblivious case, the decision statistic does not depend on the network delays. This yields a Bayesian change detection problem with a tradeoff between the random network delay and the decision delay; a higher sampling rate reduces the decision delay but increases the random access delay. Under periodic sampling, in the network--oblivious case, the structure of the optimal stopping rule is the same as that without the network, and the optimal change detection delay decouples into the network delay and the optimal decision delay without the network. In the network--aware case, the optimal stopping problem is analysed as a partially observable Markov decision process, in which the states of the queues and delays in the network need to be maintained. A sufficient statistic for decision is found to be the network-state and the posterior probability of change having occurred given the measurements received and the state of the network. The optimal regimes are studied using simulation.Comment: To appear in ACM Transactions on Sensor Networks. A part of this work was presented in IEEE SECON 2006, and Allerton 201

How do incorrect results change the processing of arithmetic information? Evidence from a divided visual field experiment

Despite several recent important developments in understanding numerical processing of both isolated numbers and numbers in the context of arithmetic equations, the relative impact of congruency on high, compared to low, level processing remains unclear. The current study investigated hemispheric differences in the processing of arithmetic material, as a function of semantic and perceptual congruency, using a delayed answer verification task and divided visual field paradigm. A total of 37 participants (22 females and 15 males, mean age 30.06, SD 9.78) were presented unilaterally or bilaterally with equation results that were either correct or incorrect and had a consistent or inconsistent numerical notation. Statistical analyses showed no visual field differences in a notation consistency task, whereas when judgements had to be made on mathematical accuracy there was a right visual field advantage for incorrect equations that were notation consistent. These results reveal a clear differential processing of arithmetic information by the two cerebral hemispheres with a special emphasis on erroneous calculations. Faced with incorrect results and with a consistent numerical notation, the left hemisphere outperforms its right counterpart in making mathematical accuracy decisions

Nitric Oxide Is Involved in Heavy Ion-Induced Non-Targeted Effects in Human Fibroblasts

Previously, we investigated the dose response for chromosomal aberration (CA) for exposures corresponding to less than one particle traversal per cell nucleus by high energy and charge (HZE) particles, and showed that the dose responses for simple exchanges for human fibroblast irradiated under confluent culture conditions were best fit by non-linear models motivated by a non-targeted effect (NTE). Our results suggested that the simple exchanges in normal human fibroblasts have an important NTE contribution at low particle fluence. Nitric oxide (NO) has been reported as a candidate for intercellular signaling for NTE in many studies. In order to estimate the contribution of NTE components in induced CA, we measured CA with and without an NO scavenger in normal skin fibroblasts cells after exposure to 600 MeV/u and 1 GeV/u 56Fe ions, less than one direct particle traversal per cell nucleus. Yields of CA were significantly lower in fibroblasts exposed to the NO scavenger compared to controls, suggesting involvement of NO in cell signaling for induction of CA. Media transferred from irradiated cells induced CA in non-irradiated cells, and this effect was abrogated with NO scavengers. Our results strongly support the importance of NTE contributions in the formation of CA at low-particle fluence in fibroblasts. View Full-Tex

Giotto navigation support

Cooperative efforts between NASA and the European Space Agency (ESA) in supporting the flight of Giotto to Halley's Comet included prelaunch checks of ESA navigation software and delivery of validated DSN radio metric tracking data during the mission. Effects of drag from passing through the coma are seen in data received pre and post encounter. The post encounter Giotto trajectory provides a solar occultation in January 1988, prior to returning to the Earth in 1990 for possible retargeting to yet another comet

Improved Memoryless RNS Forward Converter Based on the Periodicity of Residues

The residue number system (RNS) is suitable for DSP architectures because of its ability to perform fast carry-free arithmetic. However, this advantage is over-shadowed by the complexity involved in the conversion of numbers between binary and RNS representations. Although the reverse conversion (RNS to binary) is more complex, the forward transformation is not simple either. Most forward converters make use of look-up tables (memory). Recently, a memoryless forward converter architecture for arbitrary moduli sets was proposed by Premkumar in 2002. In this paper, we present an extension to that architecture which results in 44% less hardware for parallel conversion and achieves 43% improvement in speed for serial conversions. It makes use of the periodicity properties of residues obtained using modular exponentiation

Applications of molecular markers for bacterial blight resistant varieties in rice (Oryza sativa L.)

Bacterial blight is one of devasting disease in almost all rice growing countries. The most effective, eco-nomic and environmental strategy for control of this disease is to develop rice varieties with genetic resistance. However, new pathotype has overcome single gene for resistance in the new cultivars. So, plant breeders are con-centrating to develop high yielding varieties with durable resistance using novel technologies. Molecular marker technology has progressed tremendously in the past decade for genetic improvement of field crops. Molecular markers can improve efficiency of breeding in different ways for trait in segregating population like identify plants with target gene in maximum recovery portion of recurrent parent. The transfer of two or three genes into single variety with the help of molecular marker is expected to lead to more durable resistance. Thus, thus review describes progress made in the development of bacterial blight resistance rice varieties using Marker Assisted Selection

FIR Filter Implementation by Efficient Sharing of Horizontal and Vertical Common Sub-expressions

No abstract availabl

Political and socio-economic instability: does it have a role in the HIV/AIDS epidemic in sub-Saharan Africa?

(Case studies from selected countries)Many sub-Saharan African countries are confronted by the HIV/AIDS epidemic. This article reviews academic literature in the social sciences and health to discover why HIV/AIDS has become an epidemic in sub-Saharan Africa and not in other parts of the world. This was studied by examining the social determinants of diminishment of tradition and social cohesion in terms of political, social and economic problems. Four countries in this region were selected for this case study, namely South Africa, Botswana, Uganda and Zimbabwe. The findings showed that instability in socio-economic and political aspects in these nations was responsible for creating a suitable environment for the spread of HIV/AIDS infection.  This paper concludes by using the theories of collective action/responsibility and social cohesion to hypothesise that the breakdown of social ties due to various kinds of conflicts and unrest is one of the main contributors to the HIV/AIDS epidemic.Keywords: HIV, violence, social cohesion, connectivity, Prem-Achilles hypothesis, sub-Saharan Africa.De nombreux pays sub-sahariens africains sont confrontés á l’épidémie du VIH/SIDA. Cet article des revues de la littérature académique des sciences sociales et de la santé á pour but de découvrir pourquoi le VIH/SIDA est devenu une épidémie en Afrique sub-saharienne par rapport aux autres parties du monde. Ceci a été étudié en examinant les déterminants sociaux de la diminution de la tradition et la cohésion sociale en termes de problèmes politiques, sociaux et économiques. Pour ce cas d’études 4 pays dans cette région ont été sélectionnés, à savoir l’Afrique du Sud, le Botswana, l’Ouganda, et le Zimbabwe. Les résultats ont montré que l’instabilité politique et socio-économique est responsable de la création d’un environnement favorable á la propagation de l’infection du VIH/SIDA. Ce document conclus en utilisant la théorie de l’action collective/responsabilité et la cohésion sociale l’hypothèse que la rupture des liens sociaux en raison de divers types de conflits et de troubles reste l’un des principaux contributeurs á la pandémie du VIH/SIDA

Impact Of Air Pollution In Tamil Nadu

This paper outlines the impact of air pollution in Tamil Nadu. Air pollution is the any form of solid, liquid and gaseous substance present in the atmosphere that may or tend to be injurious to human beings, other living creatures, plants, property or the environment in general. Air pollution is probably one of the most serious environmental problems confronting our civilization today. Most often, it is caused by human activitiessuch as mining, construction, transportation, industrial work, agriculture, smelting, etc. However, natural processes such as volcanic eruptions and wildfires may also pollute the air, but their occurrence is rare and they usually have a local effect, unlike human activities that are ubiquitous causes of air pollution and contribute to the global pollution of the air every single day