A Novel Method for Event Detection using Wireless Sensor Networks

Reliable event detection is one of the hottest research areas in the wireless sensor networks field these days. Battlefield monitoring, fire detection, nuclear and chemical attack, and gas leak detection are examples of the event detection applications. One of the main goals to WSNs is transmitting the sensed data to the sink (Base station) in an efficient way with minimum energy usage to achieve high degree of event detection reliability. Thus, Its very important to determine the reliability degree to know the number of data that are required to receive at the sink to achieve the desired reliability. Most of the previous research works proposed different solutions for reliable event detection. The idea of all these solutions is based on increasing the amount of the transmitted data to the sink by controlling the sources reporting rate. However, rising the reporting rate may lead to losing the transmitted data due to the network congestion and packets collision, and this is related to the restricted resources capacity of the network\u27s sensor nodes. Therefore, in this paper, a new indoor method to achieve quality based event reliability for critical event detection have been implemented using hardware sensor nodes (Waspmote). The idea of this method is depending on sending the sensed data to the sink using a node called Cluster Head (CH) in a sequence according to their priority from the high to the low. The network nodes have been deployed in the experiment area into clusters, and each cluster have a CH node which work on collecting the cluster members readings and reorder it in descending order to send it next to the sink. The probability to deliver the important data to detect the event to the sink will increase by using this new method. The proposed mechanism intends to improve the event detection reliability, minimize the end-to-end delay, and increase the network lifetime. Experiments results show that the proposed method achieved a good the performance in terms of packets delivery, event detection, and end-to-end delay

An investigation into linearity with cumulative emissions of the climate and carbon cycle response in HadCM3LC

We investigate the extent to which global mean temperature, precipitation, and the carbon cycle are constrained by cumulative carbon emissions throughout four experiments with a fully coupled climate-carbon cycle model. The two paired experiments adopt contrasting, idealised approaches to climate change mitigation at different action points this century, with total emissions exceeding two trillion tonnes of carbon in the later pair. Their initially diverging cumulative emissions trajectories cross after several decades, before diverging again. We find that their global mean temperatures are, to first order, linear with cumulative emissions, though regional differences in temperature of up to 1.5K exist when cumulative emissions of each pair coincide. Interestingly, although the oceanic precipitation response scales with cumulative emissions, the global precipitation response does not, due to a decrease in precipitation over land above cumulative emissions of around one trillion tonnes of carbon (TtC). Most carbon fluxes and stores are less well constrained by cumulative emissions as they reach two trillion tonnes. The opposing mitigation approaches have different consequences for the Amazon rainforest, which affects the linearity with which the carbon cycle responds to cumulative emissions. Averaged over the two fixed-emissions experiments, the transient response to cumulative carbon emissions (TCRE) is 1.95 K TtC-1, at the upper end of the IPCC’s range of 0.8-2.5 K TtC-1

A Non-Traditional Assessment of Learning: The School for New Learning\u27s Unified Approach to Learning and Life. Final Report submitted to the Fund for the Improvement of Postsecondary Institutions

For the last two years, DePaul University\u27s School for New Learning has been funded by the Fund for the Improvement of Postsecondary Education (FIPSE) to articulate, refine and evaluate a competency-based framework for adult learners. The result--an unusual GENERALIST approach to competence--provides the conceptual underpinnings for the now fully realized school. Rather than dwell on a demographic evaluation report (although statistical information is available), the Project Directors have chosen to present the philosophy, principles and processes which shape this new definition of a B.A. degree. Central to the School\u27s design is that it provide an environment which is learner-centered. Thus, it has been exciting to discover in the course of this project an historical foundation for key ideas in this program--the roots of the School\u27s nontraditional approach to unifying learning and life. These ideas will be presented in the following paper. Documents produced for the development of the entire program (which was never seen as distinct from the funded project) are appended

Carbon Isotope Constraints on the Deglacial CO2 Rise from Ice Cores

The stable carbon isotope ratio of atmospheric CO2 (d13Catm) is a key parameter in deciphering past carbon cycle changes. Here we present d13Catm data for the past 24,000 years derived from three independent records from two Antarctic ice cores. We conclude that a pronounced 0.3 per mil decrease in d13Catm during the early deglaciation can be best explained by upwelling of old, carbon-enriched waters in the Southern Ocean. Later in the deglaciation, regrowth of the terrestrial biosphere, changes in sea surface temperature, and ocean circulation governed the d13Catm evolution. During the Last Glacial Maximum, d13Catm and atmospheric CO2 concentration were essentially constant, which suggests that the carbon cycle was in dynamic equilibrium and that the net transfer of carbon to the deep ocean had occurred before then

Holocene carbon-cycle dynamics based on CO2 trapped in ice at Taylor Dome, Antarctica

A high-resolution ice-core record of atmospheric CO2 concentration over the Holocene epoch shows that the global carbon cycle has not been in steady state during the past 11,000 years. Analysis of the CO2 concentration and carbon stable-isotope records, using a one-dimensional carbon-cycle model,uggests that changes in terrestrial biomass and sea surface temperature were largely responsible for the observed millennial-scale changes of atmospheric CO2 concentrations

Destabilization of the thermohaline circulation by transient perturbations to the hydrological cycle

We reconsider the problem of the stability of the thermohaline circulation as described by a two-dimensional Boussinesq model with mixed boundary conditions. We determine how the stability properties of the system depend on the intensity of the hydrological cycle. We define a two-dimensional parameters' space descriptive of the hydrology of the system and determine, by considering suitable quasi-static perturbations, a bounded region where multiple equilibria of the system are realized. We then focus on how the response of the system to finite-amplitude surface freshwater forcings depends on their rate of increase. We show that it is possible to define a robust separation between slow and fast regimes of forcing. Such separation is obtained by singling out an estimate of the critical growth rate for the anomalous forcing, which can be related to the characteristic advective time scale of the system.Comment: 37 pages, 8 figures, submitted to Clim. Dy

Global warming will affect the maximum potential abundance of boreal plant species

Forecasting the impact of future global warming on biodiversity requires understanding how temperature limits the distribution of species. Here we rely on Liebig's Law of Minimum to estimate the effect of temperature on the maximum potential abundance that a species can attain at a certain location. We develop 95%‐quantile regressions to model the influence of effective temperature sum on the maximum potential abundance of 25 common understory plant species of Finland, along 868 nationwide plots sampled in 1985. Fifteen of these species showed a significant response to temperature sum that was consistent in temperature‐only models and in all‐predictors models, which also included cumulative precipitation, soil texture, soil fertility, tree species and stand maturity as predictors. For species with significant and consistent responses to temperature, we forecasted potential shifts in abundance for the period 2041–2070 under the IPCC A1B emission scenario using temperature‐only models. We predict major potential changes in abundance and average northward distribution shifts of 6–8 km yr−1. Our results emphasize inter‐specific differences in the impact of global warming on the understory layer of boreal forests. Species in all functional groups from dwarf shrubs, herbs and grasses to bryophytes and lichens showed significant responses to temperature, while temperature did not limit the abundance of 10 species. We discuss the interest of modelling the ‘maximum potential abundance’ to deal with the uncertainty in the predictions of realized abundances associated to the effect of environmental factors not accounted for and to dispersal limitations of species, among others. We believe this concept has a promising and unexplored potential to forecast the impact of specific drivers of global change under future scenarios.202