Not All Wireless Sensor Networks Are Created Equal: A Comparative Study On Tunnels

Wireless sensor networks (WSNs) are envisioned for a number of application scenarios. Nevertheless, the few in-the-field experiences typically focus on the features of a specific system, and rarely report about the characteristics of the target environment, especially w.r.t. the behavior and performance of low-power wireless communication. The TRITon project, funded by our local administration, aims to improve safety and reduce maintenance costs of road tunnels, using a WSN-based control infrastructure. The access to real tunnels within TRITon gives us the opportunity to experimentally assess the peculiarities of this environment, hitherto not investigated in the WSN field. We report about three deployments: i) an operational road tunnel, enabling us to assess the impact of vehicular traffic; ii) a non-operational tunnel, providing insights into analogous scenarios (e.g., underground mines) without vehicles; iii) a vineyard, serving as a baseline representative of the existing literature. Our setup, replicated in each deployment, uses mainstream WSN hardware, and popular MAC and routing protocols. We analyze and compare the deployments w.r.t. reliability, stability, and asymmetry of links, the accuracy of link quality estimators, and the impact of these aspects on MAC and routing layers. Our analysis shows that a number of criteria commonly used in the design of WSN protocols do not hold in tunnels. Therefore, our results are useful for designing networking solutions operating efficiently in similar environments

Chernoff Dimensionality Reduction-Where Fisher Meets FKT

Well known linear discriminant analysis (LDA) based on the Fisher criterion is incapable of dealing with heteroscedasticity in data. However, in many practical applications we often encounter heteroscedastic data, i.e., within-class scatter matrices can not be expected to be equal. A technique based on the Chernoff criterion for linear dimensionality reduction has been proposed recently. The technique extends well-known Fisher\u27s LDA and is capable of exploiting information about heteroscedasticity in the data. While the Chernoff criterion has been shown to outperform the Fisher\u27s, a clear understanding of its exact behavior is lacking. In addition, the criterion, as introduced, is rather complex, making it difficult to clearly state its relationship to other linear dimensionality reduction techniques. In this paper, we show precisely what can be expected from the Chernoff criterion and its relations to the Fisher criterion and Fukunaga-Koontz transform. Furthermore, we show that a recently proposed decomposition of the data space into four subspaces is incomplete. We provide arguments on how to best enrich the decomposition of the data space in order to account for heteroscedasticity in the data. Finally, we provide experimental results validating our theoretical analysis

Is There Light at the Ends of the Tunnel? Wireless Sensor Networks for Adaptive Lighting in Road Tunnels

Existing deployments of wireless sensor networks (WSNs) are often conceived as stand-alone monitoring tools. In this paper, we report instead on a deployment where the WSN is a key component of a closed-loop control system for adaptive lighting in operational road tunnels. WSN nodes along the tunnel walls report light readings to a control station, which closes the loop by setting the intensity of lamps to match a legislated curve. The ability to match dynamically the lighting levels to the actual environmental conditions improves the tunnel safety and reduces its power consumption. The use of WSNs in a closed-loop system, combined with the real-world, harsh setting of operational road tunnels, induces tighter requirements on the quality and timeliness of sensed data, as well as on the reliability and lifetime of the network. In this work, we test to what extent mainstream WSN technology meets these challenges, using a dedicated design that however relies on wellestablished techniques. The paper describes the hw/sw architecture we devised by focusing on the WSN component, and analyzes its performance through experiments in a real, operational tunnel

Options and implications for agricultural production - Report of Task 7: Final Report

CAPRESE has led to a better understanding of the potential of using specific land management practices in preserving and increasing the stock of organic carbon in the agricultural soils of the EU. The scientific literature relating to a range of carbon sequestration measures has been synthesised and evaluated for their potential applicability. Land management has a significant impact on SOC stocks with a number of measures clearly leading to carbon emissions. Conversely, a number of practices can be used to preserve and increase SOC levels. A novel modelling platform suggests that existing assessments of the SOC stock associated with agricultural topsoil in the EU may be over-estimating the current pool by around 24%. The project shows a topsoil SOC pool of 16 Gt., 7.4 and 5.4 Gt respectively between arable and pasture. The model shows that grassland conversion to cropland can have a strong negative impact on the overall C balance in the EU and consequently should be preserved (together with peatlands). Promising management practices for sequestering SOC include cover crops, complex rotation including residue management and reduced tillage. Such measures give C sequestration rates of up to 0.5 t C ha-1 yr-1. However, their effect was strongly dependent on the spatial and temporal extent considered and the scenarios clearly show strong regional differences in the performance of measures. An integrated approach in which measures are combined, could have a significant impact. An implementation scenario of a 12% uptake of mitigation measures gave a cumulated sequestration value of 101 Mt by 2020. Increased areas and variation in implementation patterns could give rise to higher values. Extensive and comparable data on the financial aspects of the implementation and cost-benefit of measures are limited or absent. Substantial effort is required to address these issues. Simplistic scenario analysis shows that on the basis of a conservative implementation of mitigation measures, a SOC stock with a perceived trading value of €500 million could be established by 2020. Such values imply that the implementation of the practices considered would be cost efficient compared to non-agricultural mitigation measures While calculations at farm-scale are difficult, agricultural systems and proportion of land that could be made available to SOC management schemes, there is a perceived positive cost-benefit to C preservation and mitigation measures. Return for grasslands where sequestration and preservation rates are higher would clearly be greater. A cost benefit calculated with the CAPRI (FT) model. Indicated no loss in agricultural income from a 5% conversion to grassland with in turn resulted in a value of the CO2 sequestered in the soil as €20.98 t-1 CO2. Comprehensive data on the impact of the implementation of the measures on production and the market are difficult to define as these macro-scale models do not consider the technical details associated with the specific measures that need to be applied to sequester SOC. However, the studies tend to indicate that that impacts on production could occur but these would be of low magnitude and regionally variable. From an economic perspective, the financial implications of the grassland scenario implemented in CAPRI (FT) model, it can be stated that the CAP premium implications are negligible. This is derived from the fact that as most of the direct payments premiums are now decoupled from production the change in the land use derived from the scenario setting is not affecting the total amount of the direct payments. From a policy perspective, it is important that existing good stewardship of land for maintaining existing SOC stocks should be recognised as a premium in comparison to simply sequestration of OC. Such an approach would be an incentive not to engage in conversion of organic-rich soils to other uses which could lead to a decrease in SOC stocks.JRC.H.5-Land Resources Managemen

Compensatory ion transport buffers daily protein rhythms to regulate osmotic balance and cellular physiology

Abstract: Between 6–20% of the cellular proteome is under circadian control and tunes mammalian cell function with daily environmental cycles. For cell viability, and to maintain volume within narrow limits, the daily variation in osmotic potential exerted by changes in the soluble proteome must be counterbalanced. The mechanisms and consequences of this osmotic compensation have not been investigated before. In cultured cells and in tissue we find that compensation involves electroneutral active transport of Na+, K+, and Cl− through differential activity of SLC12A family cotransporters. In cardiomyocytes ex vivo and in vivo, compensatory ion fluxes confer daily variation in electrical activity. Perturbation of soluble protein abundance has commensurate effects on ion composition and cellular function across the circadian cycle. Thus, circadian regulation of the proteome impacts ion homeostasis with substantial consequences for the physiology of electrically active cells such as cardiomyocytes

The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis

Background A growing body of research identifies the harmful effects that adverse childhood experiences (ACEs; occurring during childhood or adolescence; eg, child maltreatment or exposure to domestic violence) have on health throughout life. Studies have quantified such effects for individual ACEs. However, ACEs frequently co-occur and no synthesis of findings from studies measuring the effect of multiple ACE types has been done. Methods In this systematic review and meta-analysis, we searched five electronic databases for cross-sectional, case-control, or cohort studies published up to May 6, 2016, reporting risks of health outcomes, consisting of substance use, sexual health, mental health, weight and physical exercise, violence, and physical health status and conditions, associated with multiple ACEs. We selected articles that presented risk estimates for individuals with at least four ACEs compared with those with none for outcomes with sufficient data for meta-analysis (at least four populations). Included studies also focused on adults aged at least 18 years with a sample size of at least 100. We excluded studies based on high-risk or clinical populations. We extracted data from published reports. We calculated pooled odds ratios (ORs) using a random-effects model. Findings Of 11 621 references identified by the search, 37 included studies provided risk estimates for 23 outcomes, with a total of 253 719 participants. Individuals with at least four ACEs were at increased risk of all health outcomes compared with individuals with no ACEs. Associations were weak or modest for physical inactivity, overweight or obesity, and diabetes (ORs of less than two); moderate for smoking, heavy alcohol use, poor self-rated health, cancer, heart disease, and respiratory disease (ORs of two to three), strong for sexual risk taking, mental ill health, and problematic alcohol use (ORs of more than three to six), and strongest for problematic drug use and interpersonal and self-directed violence (ORs of more than seven). We identified considerable heterogeneity (I 2 of > 75%) between estimates for almost half of the outcomes. Interpretation To have multiple ACEs is a major risk factor for many health conditions. The outcomes most strongly associated with multiple ACEs represent ACE risks for the next generation (eg, violence, mental illness, and substance use). To sustain improvements in public health requires a shift in focus to include prevention of ACEs, resilience building, and ACE-informed service provision. The Sustainable Development Goals provide a global platform to reduce ACEs and their life-course effect on health. Funding Public Health Wales. © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licens

On Neighbors, Groups and Application Invariants in Mobile Wireless Sensor Networks

The miniaturization and energy-efficient operation of wireless sensor networks (WSNs) provides unprecedented opportunities for monitoring mobile entities. The motivation for this thesis is drawn from real-world applications including monitoring wildlife, assisted living, and logistics. Nevertheless, mobility unveils a series of problems that do not arise in fixed scenarios. Through applications, we distill three of those, as follows. Neighbor discovery, or knowing the identity of surrounding nodes, is the precondition for any communication between nodes. As compared to other existing solutions, we provide a framework that approaches the problem from the perspectives of latency (the time required to detect an amount of contacts), lifetime (the time nodes are expected to last) and probability (the fraction of contacts guaranteed to be detected within a given latency). By formalizing neighbor discovery as an optimization problem, we obtain a significant improvement w.r.t. the state-of-art. We offer a solver providing the optimal configuration and an implementation for popular WSN devices. Group membership, or knowing the identity of the transitively connected nodes, can be either the direct answer to a requirement (e.g., caring for people that are not self-sufficient), or a building-block for higher-level abstractions. Earlier works on the same problem target either less constrained devices such as PDAs or laptops or, when targeting WSN devices, provide only post-deployment information on the group. Instead, we provide three protocols that cover the solution space. All our protocols empower each node with a run-time global view of the group composition. Finally, we focus on the behavior of the processes monitored by WSNs. We present a system that validates whether global invariants describing the safe behavior of a monitored system are satisfied. Although similar problems have been tackled before, the invariants we target are more complex and our system evaluates them in the network, at run-time. We focus on invariants that are expressed as first-order logic formulas over the state of multiple nodes. The requirement for monitoring invariants arises in both fixed and mobile environments; we design and implement an efficient solution for each. Noteworthy is that the solution targeting mobility bestows each node with an eventually consistent view on the satisfaction of the monitored invariants; in this context, the group membership algorithms play the role of global failure detectors

DICE: Monitoring Global Invariants of Physical Processes using Wireless Sensor Networks

Wireless sensor networks (WSNs) enable decentralized architectures to monitor the behavior of physical processes and to detect deviations from a specified “safe” behavior, e.g., to check the operation of control loops. Such correct behavior is typically expressed by global invariants over the state of different sensors or actuators. Nevertheless, to leverage the computing capabilities of WSN nodes, the application intelligence needs to reside inside the network. The task of ensuring that the monitored processes behave safely thus becomes inherently distributed, and hence more complex. In this paper we present DICE, a system enabling WSN-based distributed monitoring of global invariants. A DICE invariant is expressed by predicates defined over the state of multiple WSN nodes, e.g., the expected state of actuators based on given sensed environ- mental conditions. Our modular design allows two alternative protocols for detecting invariant violations: both perform in-network aggregation but with different degrees of decentralization, therefore supporting scenarios with different network and data dynamics. We characterize and compare the two protocols using large-scale simulations and a real-world testbed. Our results indicate that invariant violations are detected in a timely and energy-efficient manner. For instance, in a 225-node 15-hop network, invariant violations are detected in less than a second and with only a few packets sent by each node