Reliability Integrated Intrusion Detection System for Isolating Black Hole Attack in MANET

905-908Mobile ad hoc network (MANET) is a temporary network which can be utilized for emergency applications. It is easy to deploy the attackers in the network. The network performance may get degraded due to the presence of attackers. Black hole attack is the major attack which will totally violate the network rules and degrade the routing process. In this research, the Reliability Integrated Intrusion Detection System (RIIDS) is used for isolating the black hole attacks. It contains three phases. In first phase, the node forwarding ration is estimated to provide node reliability. In second phase, route reliability metric is evaluated to obtain the effective routes which can withstand the attackers. In third phase, objective function with effective routing strategy is adopted to detect attackers and isolate them by discovering alternate routes. The simulation results are analyzed using AODV protocol in terms of various performance metrics i.e. attacker detection ratio, queuing delay, packet delivery ratio and confidentiality

Reliability Integrated Intrusion Detection System for Isolating Black Hole Attack in MANET

Mobile ad hoc network (MANET) is a temporary network which can be utilized for emergency applications. It is easy to deploy the attackers in the network. The network performance may get degraded due to the presence of attackers. Black hole attack is the major attack which will totally violate the network rules and degrade the routing process. In this research, the Reliability Integrated Intrusion Detection System (RIIDS) is used for isolating the black hole attacks. It contains three phases. In first phase, the node forwarding ration is estimated to provide node reliability. In second phase, route reliability metric is evaluated to obtain the effective routes which can withstand the attackers. In third phase, objective function with effective routing strategy is adopted to detect attackers and isolate them by discovering alternate routes. The simulation results are analyzed using AODV protocol in terms of various performance metrics i.e. attacker detection ratio, queuing delay, packet delivery ratio and confidentiality

Constraints on methane emissions in North America from future geostationary remote-sensing measurements

The success of future geostationary (GEO) satellite observation missions depends on our ability to design instruments that address their key scientific objectives. In this study, an Observation System Simulation Experiment (OSSE) is performed to quantify the constraints on methane (CH4) emissions in North America obtained from shortwave infrared (SWIR), thermal infrared (TIR), and multi-spectral (SWIR+TIR) measurements in geostationary orbit and from future SWIR low-Earth orbit (LEO) measurements. An efficient stochastic algorithm is used to compute the information content of the inverted emissions at high spatial resolution (0.5°  ×  0.7°) in a variational framework using the GEOS-Chem chemistry-transport model and its adjoint. Our results show that at sub-weekly timescales, SWIR measurements in GEO orbit can constrain about twice as many independent flux patterns than in LEO orbit, with a degree of freedom for signal (DOF) for the inversion of 266 and 115, respectively. Comparisons between TIR GEO and SWIR LEO configurations reveal that poor boundary layer sensitivities for the TIR measurements cannot be compensated for by the high spatiotemporal sampling of a GEO orbit. The benefit of a multi-spectral instrument compared to current SWIR products in a GEO context is shown for sub-weekly timescale constraints, with an increase in the DOF of about 50 % for a 3-day inversion. Our results further suggest that both the SWIR and multi-spectral measurements on GEO orbits could almost fully resolve CH4 fluxes at a spatial resolution of at least 100 km  ×  100 km over source hotspots (emissions  >  4  ×  105 kg day−1). The sensitivity of the optimized emission scaling factors to typical errors in boundary and initial conditions can reach 30 and 50 % for the SWIR GEO or SWIR LEO configurations, respectively, while it is smaller than 5 % in the case of a multi-spectral GEO system. Overall, our results demonstrate that multi-spectral measurements from a geostationary satellite platform would address the need for higher spatiotemporal constraints on CH4 emissions while greatly mitigating the impact of inherent uncertainties in source inversion methods on the inferred fluxes

Tropospheric emissions: Monitoring of pollution (TEMPO)

TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2.1 km N/S×4.4 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) orbit, to capture the high variability present in the diurnal cycle of emissions and chemistry that are unobservable from current low-Earth orbit (LEO) satellites that measure once per day. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve ozone (O), nitrogen dioxide (NO), sulfur dioxide (SO), formaldehyde (HCO), glyoxal (CHO), bromine monoxide (BrO), IO (iodine monoxide), water vapor, aerosols, cloud parameters, ultraviolet radiation, and foliage properties. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O chemistry cycle. Multi-spectral observations provide sensitivity to O in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides these near-real-time air quality products that will be made publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with the European Sentinel-4 (S4) and Korean Geostationary Environment Monitoring Spectrometer (GEMS) instruments.Peer Reviewe

Atmospheric carbon dioxide retrieved from the Greenhouse gases Observing SATellite (GOSAT): Comparison with ground-based TCCON observations and GEOS-Chem model calculations

We retrieved column-averaged dry air mole fractions of atmospheric carbon dioxide (X_CO_2) from backscattered short-wave infrared (SWIR) sunlight measured by the Japanese Greenhouse gases Observing SATellite (GOSAT). Over two years of X_CO_2 retrieved from GOSAT is compared with X_CO_2 inferred from collocated SWIR measurements by seven ground-based Total Carbon Column Observing Network (TCCON) stations. The average difference between GOSAT and TCCON X_CO_2 for individual TCCON sites ranges from −0.87 ppm to 0.77 ppm with a mean value of 0.1 ppm and standard deviation of 0.56 ppm. We find an average bias between all GOSAT and TCCON X_CO_2 retrievals of −0.20 ppm with a standard deviation of 2.26 ppm and a correlation coefficient of 0.75. One year of XCO2 was retrieved from GOSAT globally, which was compared to global 3-D GEOS-Chem chemistry transport model calculations. We find that the latitudinal gradient, seasonal cycles, and spatial variability of GOSAT and GEOS-Chem agree well in general with a correlation coefficient of 0.61. Regional differences between GEOS-Chem model calculations and GOSAT observations are typically less than 1 ppm except for the Sahara and central Asia where a mean difference between 2 to 3 ppm is observed, indicating regional biases in the GOSAT X_CO_2 retrievals unobserved by the current TCCON network. Using a bias correction scheme based on linear regression these regional biases are significantly reduced, approaching the required accuracy for surface flux inversions

Neonatal invasive candidiasis in low- and middle-income countries: Data from the NeoOBS study.

Neonatal invasive candidiasis (NIC) has significant morbidity and mortality. Reports have shown a different profile of those neonates affected with NIC and of fluconazole-resistant Candida spp. isolates in low- and middle-income countries (LMICs) compared to high-income countries (HICs). We describe the epidemiology, Candida spp. distribution, treatment, and outcomes of neonates with NIC from LMICs enrolled in a global, prospective, longitudinal, observational cohort study (NeoOBS) of hospitalized infants <60 days postnatal age with sepsis (August 2018-February 2021). A total of 127 neonates from 14 hospitals in 8 countries with Candida spp. isolated from blood culture were included. Median gestational age of affected neonates was 30 weeks (IQR: 28-34), and median birth weight was 1270 gr (interquartile range [IQR]: 990-1692). Only a minority had high-risk criteria, such as being born <28 weeks, 19% (24/127), or birth weight <1000 gr, 27% (34/127). The most common Candida species were C. albicans (n = 45, 35%), C. parapsilosis (n = 38, 30%), and Candida auris (n = 18, 14%). The majority of C. albicans isolates were fluconazole susceptible, whereas 59% of C. parapsilosis isolates were fluconazole-resistant. Amphotericin B was the most common antifungal used [74% (78/105)], followed by fluconazole [22% (23/105)]. Death by day 28 post-enrollment was 22% (28/127). To our knowledge, this is the largest multi-country cohort of NIC in LMICs. Most of the neonates would not have been considered at high risk for NIC in HICs. A substantial proportion of isolates was resistant to first choice fluconazole. Understanding the burden of NIC in LMIC is essential to guide future research and treatment guidelines

One hand, two objects: Emergence of affordance in contexts.

Studies on affordances typically focus on single objects. We investigated whether affordances are modulated by the context, defined by the relation between 2 objects and a hand. Participants were presented with pictures displaying 2 manipulable objects linked by a functional (knifebutter), a spatial (knife-coffee mug), or by no relation. They responded by pressing a key whether the objects were related or not. To determine if observing other’s actions and understanding their goals would facilitate judgments, a hand was: a. displayed near the objects; b. grasping an object to use it; c. grasping an object to manipulate/move it; d. no hand was displayed. RTs were faster when objects were functionally rather than spatially related. Manipulation postures were the slowest in the functional context and functional postures were inhibited in the spatial context, probably due to mismatch between the inferred goal and the context. The absence of this interaction with foot responses instead of hands in Experiment 2 suggests that effects are due to motor simulation rather than to associations between context and hand-postures

One hand, two objects: Emergence of affordance in contexts.

Studies on affordances typically focus on single objects. We investigated whether affordances are modulated by the context, defined by the relation between 2 objects and a hand. Participants were presented with pictures displaying 2 manipulable objects linked by a functional (knifebutter), a spatial (knife-coffee mug), or by no relation. They responded by pressing a key whether the objects were related or not. To determine if observing other\u2019s actions and understanding their goals would facilitate judgments, a hand was: a. displayed near the objects; b. grasping an object to use it; c. grasping an object to manipulate/move it; d. no hand was displayed. RTs were faster when objects were functionally rather than spatially related. Manipulation postures were the slowest in the functional context and functional postures were inhibited in the spatial context, probably due to mismatch between the inferred goal and the context. The absence of this interaction with foot responses instead of hands in Experiment 2 suggests that effects are due to motor simulation rather than to associations between context and hand-postures

The visual encoding of tool-object affordances

The perception of tool–object pairs involves understanding their action-relationships (affordances). Here, we sought to evaluate how an observer visually encodes tool–object affordances. Eye-movements were recorded as right-handed participants freely viewed static, right-handed, egocentric tool–object images across three contexts: correct (e.g. hammer-nail), incorrect (e.g. hammer-paper), spatial/ambiguous (e.g. hammer-wood), and three grasp-types: no hand, functional grasp-posture (grasp hammer-handle), non-functional/manipulative grasp-posture (grasp hammer-head). There were three areas of interests (AOI): the object (nail), the operant tool-end (hammer-head), the graspable tool-end (hammer-handle). Participants passively evaluated whether tool–object pairs were functionally correct/incorrect. Clustering of gaze scanpaths and AOI weightings grouped conditions into three distinct grasp-specific clusters, especially across correct and spatial tool–object contexts and to a lesser extent within the incorrect tool–object context. The grasp-specific gaze scanpath clusters were reasonably robust to the temporal order of gaze scanpaths. Gaze was therefore automatically primed to grasp-affordances though the task required evaluating tool–object context. Participants also primarily focused on the object and the operant tool-end and sparsely attended to the graspable tool-end, even in images with functional grasp-postures. In fact, in the absence of a grasp, the object was foveally weighted the most, indicative of a possible object-oriented action priming effect wherein the observer may be evaluating how the tool engages on the object. Unlike the functional grasp-posture, the manipulative grasp-posture caused the greatest disruption in the object-oriented priming effect, ostensibly as it does not afford tool–object action due to its non-functional interaction with the operant tool-end that actually engages with the object (e.g., hammer-head to nail). The enhanced attention towards the manipulative grasp-posture may serve to encode grasp-intent. Results here shed new light on how an observer gathers action-information when evaluating static tool–object scenes and reveal how contextual and grasp-specific affordances directly modulate visuospatial attention