WorldWideScience

Sample records for water intrusion

  1. Intrusion and extrusion of water in hydrophobic mesopores

    OpenAIRE

    Barrat, Jean-Louis; Lefevre, Benoit; Bocquet, Lyderic; Saugey, Anthony; Vigier, Gérard; Gobin, Pierre-François; Charlaix, Elisabeth

    2003-01-01

    We present experimental and theoretical results on intrusion-extrusion cycles of water in hydrophobic mesoporous materials, characterized by independent cylindrical pores. The intrusion, which takes place above the bulk saturation pressure, can be well described using a macroscopic capillary model. Once the material is saturated with water, extrusion takes place upon reduction of the externally applied pressure; Our results for the extrusion pressure can only be understood by assuming that th...

  2. Intrusion problematic during water supply systems' operation

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Rodriguez, Jesus; Lopez-Jimenez, P. Amparo [Departamento de Ingenieria Hidraulica y Medio Ambiente, Universidad Politecnica de Valencia, Camino de Vera, s/n, 46022, Valencia (Spain); Ramos, Helena M. [Civil Engineering Department and CEHIDRO, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001, Lisbon (Portugal)

    2011-07-01

    Intrusion through leaks occurrence is a phenomenon when external fluid comes into water pipe systems. This phenomenon can cause contamination problems in drinking pipe systems. Hence, this paper focuses on the entry of external fluids across small leaks during normal operation conditions. This situation is especially important in elevated points of the pipe profile. Pressure variations can origin water volume losses and intrusion of contaminants into the drinking water pipes. This work focuses in obtaining up the physical representation on a specific case intrusion in a pipe water system. The combination of two factors is required to generate this kind of intrusion in a water supply system: on one hand the existence of at least a leak in the system; on the other hand, a pressure variation could occur during the operation of the system due to consumption variation, pump start-up or shutdown. The potential of intrusion during a dynamic or transient event is here analyzed. To obtain this objective an experimental case study of pressure transient scenario is analyzed with a small leak located nearby the transient source.

  3. Saltwater Intrusion: Climate change mitigation or just water resources management?

    Science.gov (United States)

    Ferguson, G. A.; Gleeson, T.

    2011-12-01

    Climate change and population growth are expected to substantially increase the vulnerability of global water resources throughout the 21st century. Coastal groundwater systems are a nexus of the world's changing oceanic and hydrologic systems and a critical resource for the over one billion people living in coastal areas as well as for terrestrial and offshore ecosystems. Synthesis studies and detailed simulations predict that rising sea levels could negatively impact coastal aquifers by causing saltwater to intrude landward within coastal aquifers or by saltwater inundation of coastal regions. Saltwater intrusion caused by excessive extraction is already impacting entire island nations and globally in diverse regions such as Nile River delta in Egypt, Queensland, Australia and Long Island, USA. However, the vulnerability of coastal aquifers to sea level rise and excessive extraction has not been systematically compared. Here we show that coastal aquifers are much more vulnerable to groundwater extraction than predicted sea level rise in wide-ranging hydrogeologic conditions and population densities. Low lying areas with small hydraulic gradients are more sensitive to climate change but a review of existing coastal aquifer indicates that saltwater intrusion problems are more likely to arise where water demand is high. No cases studies were found linking saltwater intrusion to sea level rise during the past century. Humans are a key driver in the hydrology of coastal aquifers and that adapting to sea level rise at the expense of better water management is misguided.

  4. Water vapor intrusions into the High Arctic during winter

    Science.gov (United States)

    Doyle, J. G.; Lesins, G.; Thackray, C. P.; Perro, C.; Nott, G. J.; Duck, T. J.; Damoah, R.; Drummond, J. R.

    2011-06-01

    The meridional transport of water vapor into the High Arctic, accompanied by dry enthalpy and clouds, impacts the surface radiative forcing. The evolution of one such moist intrusion over 9-11 February 2010 is presented. The event is analyzed using a unique blend of measurements including a new pan-Arctic retrieval of column water vapor from the Microwave Humidity Sounders, water vapor profiles from a Raman lidar and a ground-based microwave radiometer at the Polar Environment Atmospheric Research Laboratory (PEARL), in Eureka (80°N, 86°W), on Ellesmere Island in the Canadian High Arctic. A radiation model reveals the intrusion is associated with a 17 W m-2 average increase in downwelling longwave irradiance. Optically thin clouds, as observed by the lidar, contribute a further 20 W m-2 to the downwelling longwave irradiance at their peak. Intrusion events are shown to be a regular occurrence in the Arctic winter with implications for the understanding of the mechanisms driving Arctic Amplification.

  5. Hydrodynamic modeling of the intrusion phenomenon in water distribution systems; Modelacion hidrodinamica del fenomeno de intrusion en tuberia de abastecimiento

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Jimenez, Petra Amparo; Mora-Rodriguez, Jose de Jesus; Perez-Garcia, Rafael; Martinez-Solano, F. Javier [Universidad Politecnica de Valencia (Spain)

    2008-10-15

    This paper describes a strategy for the hydrodynamic modeling of the pathogen intrusion phenomenon in water distribution systems by the combination of a breakage with a depression situation. This scenario will be modeled computationally and experimentally. The phenomenon to be represented by both simulations is the same: the entrance of an external volume into the circulation of a main volume, known as a pathogen intrusion, as long as the main volume is potable water. To this end, a prototype and a computational model based on Computational Fluid Dynamics (CFD) are used, which allow visualizing the fields of speeds and pressures in a simulated form. With the comparison of the results of both models, conclusions will be drawn on the detail of the studied pathogen intrusion phenomenon. [Spanish] En el presente documento se describe una estrategia de modelacion del fenomeno hidrodinamico de la intrusion patogena en redes de distribucion de agua por combinacion de una rotura con una situacion de depresion. Este escenario sera modelado computacional y experimentalmente. El fenomeno que se desea representar con ambas simulaciones es el mismo: la entrada de un caudal externo a una conduccion para la que circula un caudal principal, denominado intrusion patogena, siempre y cuando el caudal principal sea agua potable. Para ello se dispone de un prototipo y un modelo computacional basado en la Dinamica de Fluidos Computacional (DFC de aqui en adelante), que permite visualizar los campos de velocidades y presiones de forma simulada. Con la comparacion de los resultados de ambos modelos se extraeran conclusiones sobre el detalle del fenomeno de la intrusion patogena estudiado.

  6. Water vapor isotopic composition of a stratospheric air intrusion: Measurements from the Chajnantor Plateau, Chile

    Science.gov (United States)

    Galewsky, Joseph; Samuels-Crow, Kimberly

    2014-08-01

    Measurements of water vapor isotopic composition in stratospheric air intrusions can be used to constrain the dilution of the intrusion as it mixes into the middle troposphere. The intrusion studied here occurred on 17 and 18 August 2012 with measurements obtained at an altitude of 5 km in the Chilean Andes at the Atacama Large Millimeter Array astronomical observatory on the Chajnantor Plateau. Surface ozone concentrations rose 16 ppb in 6 h and were associated with a potential vorticity intrusion on the 330 K isentropic surface. A simulated stratospheric ozone tracer reaching Chajnantor also supports the interpretation of a stratospheric intrusion. Beginning around 18:00 UTC on 17 August, the mixing ratio dropped from 3000 ppmv to 430 ppmv as the water vapor δD values dropped from -153‰ to -438‰ over 13 h while the δ18O values dropped from -20‰ to -63‰. The average mixing ratio, δD, and δ18O values during August 2012 were measured to be 1500 ppmv, -250‰, and -34‰, respectively. The minimum water vapor concentration during the intrusion was in the driest 5% of measurements made during that month, while the minimum δD and δ18O values were within the lowest 0.5% of measurements made during that month. Simple two-component models of mixing between stratospheric or upper tropospheric air with boundary layer air fail to reproduce observations, but a three-component mixing model, in which the stratospheric intrusion mixes with an upper tropospheric background air mass, as it mixes with boundary layer air on Chajnantor, matches the observations.

  7. An Excel Macro to Plot the HFE-Diagram to Identify Sea Water Intrusion Phases.

    Science.gov (United States)

    Giménez-Forcada, Elena; Sánchez San Román, F Javier

    2015-01-01

    A hydrochemical facies evolution diagram (HFE-D) is a multirectangular diagram, which is a useful tool in the interpretation of sea water intrusion processes. This method note describes a simple method for generating an HFE-D plot using the spreadsheet software package, Microsoft Excel. The code was applied to groundwater from the alluvial coastal plain of Grosseto (Tuscany, Italy), which is characterized by a complex salinization process in which sea water mixes with sulfate or bicarbonate recharge water.

  8. Modeling the Influence of River Flow and Salt Water Intrusion in the Terengganu Estuary, Malaysia

    Science.gov (United States)

    Lee, H. L.; Tangang, F.; Hamid, M. R.; Benson, Y.; Razali, M. R.

    2016-07-01

    Salinity intrusion is a major concern when the freshwater extraction station is located in the estuary. This paper attempt to predict the salt intrusion length in the upper stretch of estuary, by applying different magnitudes of freshwater discharge at the river regime. The integrated two dimensional hydrodynamics model associated with advection dispersion model was performed to investigate the salinity intrusion. The model was well calibrated and verified by the measured data undertaken during dry season. The maximum salt intrusion length to the threshold of salinity density is 1.00 ppt on the existing condition was predicted at 9.97 km from the river mouth. Moreover, with the magnitude of 100.00 m3s-1 and 30.00 m3s-1 freshwater discharges at the upstream boundary (Kpg Tanggol), it was predicted the maximum salt intrusion length was 11.84 km and 21.41 km, respectively, from the river mouth. Therefore, it was determined the minimum freshwater discharge of approximately 100.00 m3s-1 is required at the Kpg Tanggol river gauging station, in order to maintain the acceptable salinity levels at the Pulau Musang freshwater pump house. However, the actual water discharge at the Kpg Tanggol boundary station should be higher, since the minimum discharge does not take into consideration the amount of water extraction by the Pulau Musang and SATU pump stations. Further analysis is required to execute the consequences of water extraction toward the salinity intrusion in the Terengganu estuary that coupled with projected sea level rise.

  9. Analysing monthly sectorial water use and its influence on salt intrusion induced water shortage in urbanized deltas

    NARCIS (Netherlands)

    Yao, Mingtian; Yan, Dan; Kabat, Pavel; Huang, Heqing; Hutjes, Ronald W.A.; Werners, Saskia E.

    2016-01-01

    Urbanizing delta regions face seasonal water shortages induced by rising salt intrusion. Decreasing river discharge is readily listed as the major cause of water shortage events. Yet, observations of river discharge often fail to support this attribution. Evidence of the association between

  10. Confinement of water in hydrophobic nanopores: effect of the geometry on the energy of intrusion.

    Science.gov (United States)

    Karbowiak, Thomas; Weber, Guy; Bellat, Jean-Pierre

    2014-01-14

    Water confinement in the hydrophobic nanopores of highly siliceous zeolite having MFI and CHA topology is investigated by high pressure manometry coupled to differential calorimetry. Surprisingly, the intrusion of water is endothermic for MFI but exothermic for CHA. This phase transition depends on the geometry of the environment in which water is confined: channels (MFI) or cavities (CHA). The energy of intrusion is mainly governed by the change in the coordination of water molecules when they are forced to enter the nanopores and to adopt a weaker, hydrogen-bonded structure. At such a nanoscale, the properties of the molecules are governed strongly by geometrical restraints. This implies that the use of classical macroscopic equations such as Laplace-Washburn will have limitations at the molecular level.

  11. Acoustic monitoring of terrorist intrusion in a drinking water network

    NARCIS (Netherlands)

    Quesson, B.A.J.; Sheldon-Robert, M.K.; Vloerbergh, I.N.; Vreeburg, J.H.G.

    2009-01-01

    In collaboration with Kiwa Water Research, TNO (Netherlands Organisation for Applied Scientific Research) has investigated the possibilities to detect and classify aberrant sounds in water networks, using acoustic sensors. Amongst the sources of such sounds are pumps, drills, mechanical impacts, whi

  12. CONTAMINATION OF GROUNDWATER IN SRIKAKULAM COASTAL BELT DUE TO SALT WATER INTRUSION

    Directory of Open Access Journals (Sweden)

    S. Chandra Mouli

    2011-02-01

    Full Text Available Many urban centers of the country are located on the coastal tract apart from thousands of villages and industrial settlements. Water resources in coastal areas assume a special significance since anydevelopmental activity will largely depend upon availability of fresh water to meet domestic, industrial and agricultural requirements.Thisincreases the dependency upon groundwater for meeting the freshwater demand. As the region is close to the coast, the variations in the levels of water table due to excess withdrawals from wells and bore wells will cause the intrusion of seawater into the groundwater. In the present paper deals with the study of saltwater intrusion in the coastal tract of Srikakulam district, on an areal basis. From the results obtained the variation in the effect of contamination with respect to distance from shore is studied and a comparison of the contamination in open wells and bore wells is also carried out.

  13. Fracture mechanics solution of confined water progressive intrusion height of mining fracture floor

    Institute of Scientific and Technical Information of China (English)

    Lu Haifeng; Yao Duoxi; Shen Dan; Cao Jiyang

    2015-01-01

    In order to obtain the value of confined water progressive intrusion height of mining fracture floor, the analysis equation was deduced based on the fracture extension theory of the fracture mechanics. Further-more, the influence of some parameters (e.g., advancing distance of working face, water pressure, initial fracture length and its angle) on confined water progressive intrusion height were analyzed. The results indicate that tension-shearing fracture of floor is extended more easily than compression-shearing frac-ture under the same conditions. When floor fracture dip angle is less than 90?, tension-shearing extension occurs more easily on the left edge of the goaf. If fracture dip angle is larger than 90?, it occurs more easily on the right edge of the goaf. The longer the advancing distance of working face is, the greater initial frac-ture length goes; or the larger water pressure is, the greater possibility of tension-shearing extension occurs. The confined water progressive intrusion height reaches the maximum on the edge of the goaf. Field in situ test is consistent with the theoretical analysis result.

  14. Pollutant intrusion modeling in water distribution networks using artificial neural networks.

    Science.gov (United States)

    Singh, Raj Mohan; Rahul, Akhouri Ishan

    2011-07-01

    The development and implementation of water quality models for water distribution systems have been growing interest for both environment and hydraulic researchers. It is imperative that the system is able to distribute disinfectants and/or chemicals efficiently for specified quality standards and recover the actual quality of water in case of intrusion of a pollutant into the distribution network. The present work presents hydraulic and quality analysis in a typical water distribution system to obtain the concentration at the sources (pumping station or tanks) affected by typical pollutants utilizing water quality at monitoring points as inputs to artificial neural network (ANN) model. The universal function approximation property of the ANN architecture is being employed for inverse mapping to predict the water quality at the source using the water quality at arbitrary monitoring locations in the distribution system. The optimal monitoring points are identified by water age analysis. The performance evaluation results are encouraging and demonstrate the potential applicability of the methodology.

  15. Intrusion of the Bay of Bengal water into the Arabian Sea during winter monsoon and associated chemical and biological response

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Narvekar, J.; Kumar, A.; Shaji, C.; Anand, P.; Sabu, P.; Rijomon, G.; Josia, J.; Jayaraj, K.A.; Radhika, A.; Nair, K.K.C.

    Coastal Current carrying low salinity waters from the northern Bay feeds into the West India Coastal Current flowing north along the shelf in the Arabian Sea. Advection of nutrients by this intrusion triggers enhanced levels of chlorophyll near...

  16. Enteric virus infection risk from intrusion of sewage into a drinking water distribution network.

    Science.gov (United States)

    Teunis, P F M; Xu, M; Fleming, K K; Yang, J; Moe, C L; Lechevallier, M W

    2010-11-15

    Contaminants from the soil surrounding drinking water distribution systems are thought to not enter the drinking water when sufficient internal pressure is maintained. Pressure transients may cause short intervals of negative pressure, and the soil near drinking water pipes often contains fecal material due to the proximity of sewage lines, so that a pressure event may cause intrusion of pathogens. This paper presents a risk model for predicting intrusion and dilution of viruses and their transport to consumers. Random entry and dilution of virus was simulated by embedding the hydraulic model into a Monte Carlo simulation. Special attention was given to adjusting for the coincidence of virus presence and use of tap water, as independently occurring short-term events within the longer interval that the virus is predicted to travel in any branch of the distribution system. The probability that a consumer drinks water contaminated with virus is small, but when this happens the virus concentration tends to be high and the risk of infection may be considerable. The spatial distribution of infection risk is highly heterogeneous. The presence of a chlorine residual reduces the infection risk.

  17. Detection of Dry Intrusion on Water Vapor Images Over Central Europe - June 2010 TO September 2011

    Science.gov (United States)

    Novotny, J.; Dejmal, K.; Hudec, F.; Kolar, P.

    2016-06-01

    The knowledge of evaluation of the intensity of cyclogenesis which could be connected with the weather having a significant impact on Earth's surface is quite useful. If, as one of the basic assumptions, the existence of connection between dry intrusions, dry bands, tropopause height and warm dark areas distribution on water vapor images (WV images) is considered, it is possible to set up a method of detecting dry intrusions on searching and tracking areas with higher brightness temperature compared with the surrounding environment. This paper covers the period between June 2010 and September 2011 over Central Europe. The ISIS method (Instrument de Suivi dans I'Imagerie satellitaire), originally developed for detection of cold cloud tops, was used as an initial ideological point. Subsequently, this method was modified by Michel and Bouttier for usage on WV images. Some of the applied criteria and parameters were chosen with reference to the results published by Michel and Bouttier as well as by Novotny. The procedure can be divided into two steps: detection of warm areas and their tracking. Cases of detection of areas not evidently connected with dry intrusions can be solved by filtering off based on the connection between detected warm areas to the cyclonic side of jet streams and significant lowering of the tropopause.

  18. On the difficulty of modeling Circumpolar Deep Water intrusions onto the Amundsen Sea continental shelf

    Science.gov (United States)

    Nakayama, Y.; Timmermann, R.; Schröder, M.; Hellmer, H. H.

    2014-12-01

    In the Amundsen Sea, warm Circumpolar Deep Water (CDW) intrudes onto the continental shelf and flows into the ice shelf cavities of the West Antarctic Ice Sheet, resulting in high basal melt rates. However, none of the high resolution global models resolving all the small ice shelves around Antarctica can reproduce a realistic CDW flow onto the Amundsen Sea continental shelf, and previous studies show simulated bottom potential temperature at the Pine Island Ice Shelf front of about -1.8 °C. In this study, using the Finite-Element Sea ice-ice shelf-Ocean Model (FESOM), we reproduce warm CDW intrusions onto the Amundsen Sea continental shelf and realistic melt rates of the ice shelves in West Antarctica. To investigate the importance of horizontal resolution, forcing, horizontal diffusivity, and the effect of grounded icebergs, eight sensitivity experiments are conducted. To simulate the CDW intrusion realistically, a horizontal resolution of about 5 km or smaller is required. The choice of forcing is also important and the cold bias in the NCEP/NCAR reanalysis over the eastern Amundsen Sea prevents warm CDW from intruding onto the continental shelf. On the other hand, the CDW intrusion is not highly sensitive to the strength of horizontal diffusion. The effect of grounded icebergs located off Bear Peninsula is minor, but may act as a buffer to an anomalously cold year.

  19. Coastal hypoxia diminished by intrusion of open ocean water after long El Nino Events: Case study of Hong Kong waters

    Science.gov (United States)

    Lui, H. K.; Chen, C. T. A.

    2015-12-01

    Coastal regions suffer from increasing terrestrial inputs of nutrients and organic matter. Consequently, hypoxia (dissolved oxygen (DO) WPS) seawater. For instance, at station SM18 located south of Hong Kong, the summer DO minimum has generally decreased from a saturation state of about 60% to as low as 5% from 1990 to 2013. The almost anoxic condition occurred in 2011 after a La Nina event. On the other hand, the summer DO minimum reached a high value of 79% in 2004 after a long El Nino event. Meanwhile, seawater at the SEATS site also contained the highest proportion of the WPS water, reflecting the large intrusion of the WPS seawater into the SCS. Such a result illustrates a situation that coastal eutrophication and hypoxia could be worsened when the intrusion of open ocean water decreases, and vice versa.

  20. Effects of Water Intrusion on Mechanical Properties of and Crack Propagation in Coal

    Science.gov (United States)

    Yao, Qiangling; Chen, Tian; Ju, Minghe; Liang, Shun; Liu, Yapeng; Li, Xuehua

    2016-12-01

    Studying the mechanical properties of and crack propagation in coal after water intrusion is necessary to tackle a number of geological engineering problems such as those associated with underground water storage in collieries and support for underground roadways in coal mines. To study the mechanical properties and crack development, 12 coal samples with moisture contents of 0, 2.37, 3.78 and 5.29 % were prepared for acoustic emission tests under uniaxial compression. Over about 6 days, the coal samples absorbed moisture from a humidifier in three different phases. In this period, uniaxial tests show that the peak stress, elastic modulus, strain softening modulus and post-peak modulus decreased with rising moisture content in the samples while the peak strain increased. It was further found that, by analysing the relationship between the stiffness and stress and the accumulated acoustic emission counts, all the phases of crack development can be evaluated. This is useful for studying the effect of water intrusion on crack propagation and for calculating the mechanical properties of the coal such as the elastic modulus. This investigation also quantifies the percentage of the stress thresholds for crack closure, crack initiation, and crack damage that constitutes the peak stress. These stress thresholds do not change with moisture content. Our results are of great significance for water storage in coal mines, for determination of pillar dimensions in coal mines, and for expanding the knowledge base of the mechanical properties of coal and the characteristics of crack propagation.

  1. Large-Scale Aquifer Replenishment and Seawater Intrusion Control Using Recycled Water in Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Herndon, R.; Markus, M.

    2014-10-01

    In 2008, eighteen years after determining that its Talbert Seawater Barrier required expansion, the Orange County Water District started up the worldss largest indirect potable reuse facility, the Groundwater Replenishment System (GWR System). The GWR System provides a reliable potable-quality water supply to the Talbert Barrier, which consists of 109 multi-depth injection wells. The Talbert Barrier began operation in 1976 with the completion of Water Factory 21, the first project in California permitted to inject recycled water into a potable-supply aquifer. By 1990, as groundwater pumping increased, it was evident that the barriers original injection wells were incapable of maintaining protective groundwater elevations to prevent seawater intrusion. Ten years of technical planning and public outreach culminated in the decision to demolish the undersized Water Factory 21 and build a state-of-the-art advanced recycled water treatment system and expanded barrier. Barrier expansion entailed construction of over 20 new injection wells in key areas where seawater intrusion was observed. Flow modeling indicated that average barrier injection needed to be doubled to 80 m{sup 3}/min (30 mgal/day). Based on seasonal groundwater pumping patterns, model simulations indicated that the barrier should inject up to 107 m{sup 3}/min (40 mgal/day) in the summer/fall months and one-half that rate in winter/spring months to maintain a protective hydraulic barrier. With a capacity of 187 m{sup 3}/min (70 mgd), the GWR System provides all of the high-quality water that the barrier requires, with the remainder conveyed to OCWDss infiltration basins in the city of Anaheim. Five years after start-up, the expanded seawater barrier has met all expectations in terms of capacity and groundwater elevation maintenance using a reliable locally-produced water supply. (Author)

  2. Calibrating a Salt Water Intrusion Model with Time-Domain Electromagnetic Data

    DEFF Research Database (Denmark)

    Herckenrath, Daan; Odlum, Nick; Nenna, Vanessa

    2013-01-01

    Salt water intrusion models are commonly used to support groundwater resource management in coastal aquifers. Concentration data used for model calibration are often sparse and limited in spatial extent. With airborne and ground-based electromagnetic surveys, electrical resistivity models can...... are transformed to an electrical resistivity model, after which a geophysical forward response is calculated and compared with the measured geophysical data. This approach was applied for a field site in Santa Cruz County, California, where a time-domain electromagnetic (TDEM) dataset was collected...

  3. Influence of anomalous subarctic water intrusion on phytoplankton production off Baja California

    Science.gov (United States)

    Espinosa-Carreón, T. L.; Gaxiola-Castro, G.; Durazo, R.; De la Cruz-Orozco, M. E.; Norzagaray-Campos, M.; Solana-Arellano, E.

    2015-01-01

    The southern region of the California Current (CC) off Baja California represents a transitional environment, with the influence of low temperature and less saline CC water during spring and summer, and warm and salty tropical and subtropical conditions through the end of summer and autumn. From 2002 to 2006, an anomalous subarctic water (SAW) intrusion generated changes in the epipelagic ecosystem dynamics, affecting phytoplankton biomass and primary production. The goal of the present work is to show the effects of the SAW intrusion off Baja California in the phytoplankton production during the two contrasting years 2002 and 2005. Our results show that the minimum water salinity was associated with density levels of 24.6-25.5 kg m-3 in 2002 and 24.3-25.2 kg m-3 in 2005, indicating that the anomalous SAW intrusion was more pronounced in 2005. In 2005, the mean chlorophyll concentration was low (1.0 mg m-3 in some months. CHL values were significantly different between the north and south zone and among months (p<0.01). The mean values of the photosynthetic parameters (maximum light utilization coefficient (αB) and maximum photosynthesis rate (PBm)) were one order of magnitude higher in 2005 compared to 2002 (p<0.01). The primary production estimated by the Herman and Platt model and the Carr model was very different in 2002 (mean values of 907 and 143 mgC m-2 d-1 respectively), but similar in 2005 (750 and 1006 mgC m-2 d-1 respectively). The differences between models may be due to the diverse chlorophyll data used in the singular models (in situ vs. satellite-derived), and to the weight of the phytoplankton photosynthetic parameters in each algorithm. We conclude that for the present data set the Herman and Platt model is more suitable. To assess the relative importance of physical variables, as well as bio-optical and physiological parameters in primary production, we conducted a principal component analysis (PCA). There was an apparent separation between the

  4. Calibrating a salt water intrusion model with time-domain electromagnetic data.

    Science.gov (United States)

    Herckenrath, Daan; Odlum, Nick; Nenna, Vanessa; Knight, Rosemary; Auken, Esben; Bauer-Gottwein, Peter

    2013-01-01

    Salt water intrusion models are commonly used to support groundwater resource management in coastal aquifers. Concentration data used for model calibration are often sparse and limited in spatial extent. With airborne and ground-based electromagnetic surveys, electrical resistivity models can be obtained to provide high-resolution three-dimensional models of subsurface resistivity variations that can be related to geology and salt concentrations on a regional scale. Several previous studies have calibrated salt water intrusion models with geophysical data, but are typically limited to the use of the inverted electrical resistivity models without considering the measured geophysical data directly. This induces a number of errors related to inconsistent scales between the geophysical and hydrologic models and the applied regularization constraints in the geophysical inversion. To overcome these errors, we perform a coupled hydrogeophysical inversion (CHI) in which we use a salt water intrusion model to interpret the geophysical data and guide the geophysical inversion. We refer to this methodology as a Coupled Hydrogeophysical Inversion-State (CHI-S), in which simulated salt concentrations are transformed to an electrical resistivity model, after which a geophysical forward response is calculated and compared with the measured geophysical data. This approach was applied for a field site in Santa Cruz County, California, where a time-domain electromagnetic (TDEM) dataset was collected. For this location, a simple two-dimensional cross-sectional salt water intrusion model was developed, for which we estimated five uniform aquifer properties, incorporating the porosity that was also part of the employed petrophysical relationship. In addition, one geophysical parameter was estimated. The six parameters could be resolved well by fitting more than 300 apparent resistivities that were comprised by the TDEM dataset. Except for three sounding locations, all the TDEM data

  5. Contextualising Water Use in Residential Settings: A Survey of Non-Intrusive Techniques and Approaches

    Directory of Open Access Journals (Sweden)

    Davide Carboni

    2016-05-01

    Full Text Available Water monitoring in households is important to ensure the sustainability of fresh water reserves on our planet. It provides stakeholders with the statistics required to formulate optimal strategies in residential water management. However, this should not be prohibitive and appliance-level water monitoring cannot practically be achieved by deploying sensors on every faucet or water-consuming device of interest due to the higher hardware costs and complexity, not to mention the risk of accidental leakages that can derive from the extra plumbing needed. Machine learning and data mining techniques are promising techniques to analyse monitored data to obtain non-intrusive water usage disaggregation. This is because they can discern water usage from the aggregated data acquired from a single point of observation. This paper provides an overview of water usage disaggregation systems and related techniques adopted for water event classification. The state-of-the art of algorithms and testbeds used for fixture recognition are reviewed and a discussion on the prominent challenges and future research are also included.

  6. Contextualising Water Use in Residential Settings: A Survey of Non-Intrusive Techniques and Approaches.

    Science.gov (United States)

    Carboni, Davide; Gluhak, Alex; McCann, Julie A; Beach, Thomas H

    2016-05-20

    Water monitoring in households is important to ensure the sustainability of fresh water reserves on our planet. It provides stakeholders with the statistics required to formulate optimal strategies in residential water management. However, this should not be prohibitive and appliance-level water monitoring cannot practically be achieved by deploying sensors on every faucet or water-consuming device of interest due to the higher hardware costs and complexity, not to mention the risk of accidental leakages that can derive from the extra plumbing needed. Machine learning and data mining techniques are promising techniques to analyse monitored data to obtain non-intrusive water usage disaggregation. This is because they can discern water usage from the aggregated data acquired from a single point of observation. This paper provides an overview of water usage disaggregation systems and related techniques adopted for water event classification. The state-of-the art of algorithms and testbeds used for fixture recognition are reviewed and a discussion on the prominent challenges and future research are also included.

  7. Hydrochemical investigations for delineating salt-water intrusion into the coastal aquifer of Maharlou Lake, Iran

    Science.gov (United States)

    Jahanshahi, Reza; Zare, Mohammad

    2016-09-01

    Groundwater quality depends on different factors such as geology, lithology, properties of aquifer, land use, the physical condition of boundaries etc. Studying these factors can help users to manage groundwater quality. This study deals with the groundwater quality of an aquifer located in the southeastern part of Maharlou salt lake, Iran. This lake is located in the southeast of Shiraz and is the outlet of Shiraz sewages. Due to overexploitation of groundwater from the aquifer, the gradient of water table is from the lake towards the aquifer and therefore, saline water migrates to the aquifer. The phenomenon of salt water intrusion contributes to the deterioration of groundwater. In this research, groundwater types, maps of iso EC and iso ions, ion exchange in the mixing of fresh and salt water, salinity variation of the groundwater in the profile of well water column, and the salinity-time variation of the groundwater were studied. The gradual increase of the salinity of groundwater with depth from top to down in the aquifer indicates that salt water is located under fresh water. The time variation of physical and chemical parameters in the groundwater discharged from a well shows that the saline water in the bottom of the aquifer moves upward and destroys the quality of groundwater in the study area. Furthermore, Sachoun geological formation formed by evaporate deposits and evaporation from shallow groundwater are two other factors which decrease the groundwater quality.

  8. Study on sea water intrusion into palaeochannels on south coastal plain of the Laizhou Bay by the Bohai Sea

    Institute of Scientific and Technical Information of China (English)

    韩美

    2003-01-01

    The palaeochannel evolution in the study region is divided into four stages by such meth-ods as 14C dating. Sea water intrusion through palaeochannels has been studied as a focal point.Palaeochannds are the main passageways through which the sea water intrudes at a higher speed,through many means and in a changeable dynamic state.

  9. Characterisation of sea-water intrusion in the Pioneer Valley, Australia using hydrochemistry and three-dimensional numerical modelling

    Science.gov (United States)

    Werner, A. D.; Gallagher, M. R.

    2006-12-01

    Sea-water intrusion is actively contaminating fresh groundwater reserves in the coastal aquifers of the Pioneer Valley, north-eastern Australia. A three-dimensional sea-water intrusion model has been developed using the MODHMS code to explore regional-scale processes and to aid assessment of management strategies for the system. A sea-water intrusion potential map, produced through analyses of the hydrochemistry, hydrology and hydrogeology, offsets model limitations by providing an alternative appraisal of susceptibility. Sea-water intrusion in the Pioneer Valley is not in equilibrium, and a potential exists for further landward shifts in the extent of saline groundwater. The model required consideration of tidal over-height (the additional hydraulic head at the coast produced by the action of tides), with over-height values in the range 0.5-0.9 m giving improved water-table predictions. The effect of the initial water-table condition dominated the sensitivity of the model to changes in the coastal hydraulic boundary condition. Several salination processes are probably occurring in the Pioneer Valley, rather than just simple landward sea-water advancement from “modern” sources of marine salts. The method of vertical discretisation (i.e. model-layer subdivision) was shown to introduce some errors in the prediction of water-table behaviour.

  10. Social Perception of Public Water Supply Network and Groundwater Quality in an Urban Setting Facing Saltwater Intrusion and Water Shortages.

    Science.gov (United States)

    Alameddine, Ibrahim; Jawhari, Gheeda; El-Fadel, Mutasem

    2017-04-01

    Perceptions developed by consumers regarding the quality of water reaching their household can affect the ultimate use of the water. This study identified key factors influencing consumers' perception of water quality in a highly urbanized coastal city, experiencing chronic water shortages, overexploitation of groundwater, and accelerated saltwater intrusion. Household surveys were administered to residents to capture views and perceptions of consumed water. Concomitantly, groundwater and tap water samples were collected and analyzed at each residence for comparison with perceptions. People's rating of groundwater quality was found to correlate to the measured water quality both in the dry and wet seasons. In contrast, perceptions regarding the water quality of the public water supply network did not show any correlation with the measured tap water quality indicators. Logistic regression models developed to predict perception based on salient variables indicated that age, apartment ownership, and levels of total dissolved solids play a significant role in shaping perceptions regarding groundwater quality. Perceptions concerning the water quality of the public water supply network appeared to be independent of the measured total dissolved solids levels at the tap but correlated to those measured in the wells. The study highlights misconceptions that can arise as a result of uncontrolled cross-connections of groundwater to the public supply network water and the development of misaligned perceptions based on prior consumption patterns, water shortages, and a rapidly salinizing groundwater aquifer.

  11. Social Perception of Public Water Supply Network and Groundwater Quality in an Urban Setting Facing Saltwater Intrusion and Water Shortages

    Science.gov (United States)

    Alameddine, Ibrahim; Jawhari, Gheeda; El-Fadel, Mutasem

    2017-04-01

    Perceptions developed by consumers regarding the quality of water reaching their household can affect the ultimate use of the water. This study identified key factors influencing consumers' perception of water quality in a highly urbanized coastal city, experiencing chronic water shortages, overexploitation of groundwater, and accelerated saltwater intrusion. Household surveys were administered to residents to capture views and perceptions of consumed water. Concomitantly, groundwater and tap water samples were collected and analyzed at each residence for comparison with perceptions. People's rating of groundwater quality was found to correlate to the measured water quality both in the dry and wet seasons. In contrast, perceptions regarding the water quality of the public water supply network did not show any correlation with the measured tap water quality indicators. Logistic regression models developed to predict perception based on salient variables indicated that age, apartment ownership, and levels of total dissolved solids play a significant role in shaping perceptions regarding groundwater quality. Perceptions concerning the water quality of the public water supply network appeared to be independent of the measured total dissolved solids levels at the tap but correlated to those measured in the wells. The study highlights misconceptions that can arise as a result of uncontrolled cross-connections of groundwater to the public supply network water and the development of misaligned perceptions based on prior consumption patterns, water shortages, and a rapidly salinizing groundwater aquifer.

  12. Hydrological modification, saltwater intrusion, and tree water use of a Pterocarpus officinalis swamp in Puerto Rico

    Science.gov (United States)

    Colón-Rivera, Ricardo J.; Feagin, Rusty A.; West, Jason B.; López, Natalia B.; Benítez-Joubert, Rafael J.

    2014-06-01

    Tidal freshwater forested wetlands occupy a narrow ecological space determined by the balance between saltwater and freshwater inputs to the system. However, this balance is not well understood. In the Caribbean, tidal freshwater-forested wetlands dominated by Pterocarpus officinalis are vulnerable to changes in tidal influence and freshwater inputs. In this setting, the seasonal interactions of saltwater and freshwater inputs create less than ideal conditions for these forests to survive. Hence, it is crucial to have a better understanding of the hydrologic context of these and other tidal freshwater forested wetlands. We examined the extent of tidal forcing and saltwater influence in the largest Pterocarpus swamp of Puerto Rico by installing automated water level and conductivity recorders across a tidal creek transect at four different distances from the ocean, and by using water stable isotopes ratios (δD, δ18O) as natural tracers to determine the most important freshwater sources for tree transpiration. Records of water level and salinity revealed that the amount of rainfall was most influential on saltwater wedge migration in the creek for locations at the front and back of the tidal network, but that tidal dynamics were most influential at the middle section of the tidal network. Saltwater intrusion into the deepest parts of the tidal network was most prominent during sustained dry periods. Isotopic ratios of the surface water samples in the forest revealed that most of the water there was derived from freshwater runoff, but there was a seasonal change in its relative contribution to the forest hydrology. During the dry season, high δ values suggested the presence of runoff-derived water that had undergone evaporation, and saline influences were found in locations where past deforestation created preferential pathways for this water. During both seasons, δ 18O values of groundwater revealed the influence of saline water at depths 60 cm and greater near

  13. The Gulf of Aden Intermediate Water Intrusion Regulates the Southern Red Sea Summer Phytoplankton Blooms

    KAUST Repository

    Dreano, Denis

    2017-01-09

    Knowledge on large-scale biological processes in the southern Red Sea is relatively limited, primarily due to the scarce in situ, and satellite-derived chlorophyll-a (Chl-a) datasets. During summer, adverse atmospheric conditions in the southern Red Sea (haze and clouds) have long severely limited the retrieval of satellite ocean colour observations. Recently, a new merged ocean colour product developed by the European Space Agency (ESA)-the Ocean Color Climate Change Initiative (OC-CCI)-has substantially improved the southern Red Sea coverage of Chl-a, allowing the discovery of unexpected intense summer blooms. Here we provide the first detailed description of their spatiotemporal distribution and report the mechanisms regulating them. During summer, the monsoon-driven wind reversal modifies the circulation dynamics at the Bab-el-Mandeb strait, leading to a subsurface influx of colder, fresher, nutrient-rich water from the Indian Ocean. Using satellite observations, model simulation outputs, and in situ datasets, we track the pathway of this intrusion into the extensive shallow areas and coral reef complexes along the basin\\'s shores. We also provide statistical evidence that the subsurface intrusion plays a key role in the development of the southern Red Sea phytoplankton blooms.

  14. Seawater intrusion into groundwater aquifer through a coastal lake - complex interaction characterised by water isotopes (2)H and (18)O.

    Science.gov (United States)

    Gemitzi, Alexandra; Stefanopoulos, Kyriakos; Schmidt, Marie; Richnow, Hans H

    2014-01-01

    The present study investigates the complex interactions among surface waters, groundwaters and a coastal lake in northeastern Greece, using their stable isotopic composition (δ(18)O, δ(2)H) in combination with hydrogeological and hydrochemical data. Seasonal and spatial trends of water isotopes were studied and revealed that all water bodies in the study area interact. It was also shown that the aquifer's increased salinity is not due to fossil water from past geological periods, but is attributed to brackish lake water intrusion into the aquifer induced by the extensive groundwater pumping for irrigation purposes. Quantification of the contribution of the lake to the aquifer was achieved using the simple dilution formula. The isotopic signatures of the seawater and the groundwaters are considerably different, so there is a very little possibility of direct seawater intrusion into the aquifer.

  15. Geoelectric resistivity sounding for delineating salt water intrusion in the Abu Zenima area, west Sinai, Egypt

    Science.gov (United States)

    Khalil, Mohamed H.

    2006-09-01

    A direct current (dc) resistivity geoelectric technique is applied in the Abu Zenima area, West Sinai, Egypt to delineate salt water intrusion from the Gulf of Suez and evaluate the quality and some of the petrophysical parameters of the aquifer. Sixteen Schlumberger vertical electrical soundings (VES) with maximum AB/2 = 3000 m are conducted. The interpretation of the one-dimensional (1D) inversion of the acquired resistivity data could map the fresh to slightly brackish aquifer (true resistivity = 52-71 Ω m, thickness = 17-66 m), which floats on denser, more saline, deeper water (<5 Ω m). A number of water samples of the fresh aquifer are analysed to determine the total dissolved solids (TDS) concentrations (ppm). A good agreement is observed between the resistivity boundaries and the borehole data. The mutual relations between the aquifer layering, the direction of the groundwater flow and the hydrogeophysical conditions of the aquifer are investigated. The geoelectric (Dar-Zarrouk) parameters are determined and interpreted in terms of the hydraulic conductivity, transimissivity, clay content, grain size distribution and potentiality of the aquifer. The integration of the results indicates a high potentiality and a relatively good quality of the fresh to slightly brackish aquifer in the north-eastern part of the study area.

  16. Application of interleaving models to describe intrusive layers in the Deep Polar Water of the Arctic Basin

    Science.gov (United States)

    Zhurbas, Nataliya; Kuzmina, Natalia; Lyzhkov, Dmitry; Izvekova, Yulia N.

    2016-04-01

    Interleaving models of pure thermohaline and baroclinic frontal zones of finite width are applied to describe intrusions at the fronts found in the upper part of the Deep Polar Water, the Eurasian basin, under stable-stable thermohaline stratification. It is assumed that differential mixing is the main mechanism of the intrusion formation. Different parameterizations of differential mixing (Merrryfield, 2002; Kuzmina et al., 2011) are used in the models. Important parameters of interleaving such as the growth rate, vertical scale, and slope of the most unstable modes are calculated. It is found that the interleaving model of a pure thermohaline front can satisfactory describe the important parameters of intrusions observed at a thermohaline, very low baroclinicity front in the Eurasian basin, just in accordance to Merryfield (2002) findings. In the case of baroclinic front, satisfactory agreement over all the interleaving parameters is found between the model calculations and observations provided that the vertical momentum diffusivity significantly exceeds the corresponding mass diffusivity. Under specific (reasonable) constraints of the vertical momentum diffusivity, the most unstable mode has a vertical scale approximately two-three times smaller than the vertical scale of the observed intrusions. A thorough discussion of the results is presented. References Kuzmina N., Rudels B., Zhurbas V., Stipa T. On the structure and dynamical features of intrusive layering in the Eurasian Basin in the Arctic Ocean. J. Geophys. Res., 2011, 116, C00D11, doi:10.1029/2010JC006920. Merryfield W. J. Intrusions in Double-Diffusively Stable Arctic Waters: Evidence for Differential mixing? J. Phys. Oceanogr., 2002, 32, 1452-1439.

  17. Measurements of an Intrusion of Water Vapor into the High Arctic and its Effect on Wintertime Radiation

    Science.gov (United States)

    Nott, G. J.; Doyle, J. G.; Lesins, G. B.; Thackray, C. P.; Perro, C. W.; Duck, T. J.; Drummond, J. R.

    2010-12-01

    Water vapor is the most important greenhouse gas, yet little is known about it in the High Arctic during winter due to a historic lack of measurements and difficulties associated with satellite retrievals. With cold temperatures and a very stable boundary layer, the water vapor mixing ratio peaks around only 0.3 g kg-1. Any influxes of moist air from more moderate latitudes are thus likely to have a significant impact on Arctic tropospheric processes and the radiation budget. With lidar and accompanying radiometer measurements at Eureka (79°59'N, 85°56'W) we present one highly dynamic instance of such an intrusion from the winter of 2009/10. Measurements with the Canadian Network for the Detection of Atmospheric Change (CANDAC) Rayleigh/Mie/Raman lidar, shown in the figure, display distinct and seperate wet and dry air parcels during the case study. Two significant influxes of moist air (mixing ratio peaking at 1.2 g kg-1) are observed while aerosol profiles show associated cloud and precipitation. An animated map of precipitable water measured by the Microwave Humidity Sounder will be presented that shows the moist air originating over the Bering Sea and sweeping north-east into the Arctic, reaching Eureka on Feburary 9. Radiometer measurements of downwelling radiation during this time period show that the influx of water vapor alone caused a 13% increase in longwave radiation at the surface. A radiative transfer model (SBDART) has been used to isolate the effect of the water vapor, temperature, and cloud cover variations associated with this intrusion, on the overall radiation flux. Only the single event will be presented in detail however longer term data sets of water vapor indicate that such intrusions happen once or twice a month each winter. With such significant influxes of water vapor it is possible that these intrusions significantly affect the average wintertime radiation budget. Lidar measurements of water vapor mixing ratio over Eureka showing two

  18. Managing risks from virus intrusion into water distribution systems due to pressure transients.

    Science.gov (United States)

    Yang, Jian; LeChevallier, Mark W; Teunis, Peter F M; Xu, Minhua

    2011-06-01

    Low or negative pressure transients in water distribution systems, caused by unexpected events (e.g. power outages) or routine operation/maintenance activities, are usually brief and thus are rarely monitored or alarmed. Previous studies have shown connections between negative pressure events in water distribution systems and potential public health consequences. Using a quantitative microbial risk assessment (QMRA) model previously developed, various factors driving the risk of viral infection from intrusion were evaluated, including virus concentrations external to the distribution system, maintenance of a disinfectant residual, leak orifice sizes, the duration and the number of nodes drawing negative pressures. The most sensitive factors were the duration and the number of nodes drawing negative pressures, indicating that mitigation practices should be targeted to alleviate the severity of low/negative pressure transients. Maintaining a free chlorine residual of 0.2 mg/L or above is the last defense against the risk of viral infection due to negative pressure transients. Maintaining a chloramine residual did not appear to significantly reduce the risk. The effectiveness of ensuring separation distances from sewer mains to reduce the risk of infection may be system-specific. Leak detection/repair and cross-connection control should be prioritized in areas vulnerable to negative pressure transients.

  19. Assessment of the energetic performances of various ZIFs with SOD or RHO topology using high pressure water intrusion-extrusion experiments.

    Science.gov (United States)

    Khay, Ismail; Chaplais, Gérald; Nouali, Habiba; Ortiz, Guillaume; Marichal, Claire; Patarin, Joël

    2016-03-14

    The energetic performances of seven SOD or RHO-topology ZIFs, with zinc or cobalt metal cation (ZIF-8, ZIF-90, Zn(dcim)2-SALE, ZIF-67, ZIF-7, ZIF-71, ZIF-11) were evaluated using water intrusion-extrusion under high pressure. The relationship between the structural parameters (in particular the pore system SOD or RHO, the type of linker, the metal cation nature) and the intrusion pressure was studied to better understand the mechanism of water intrusion and the energetic behaviour for a given ZIF crystal type. "ZIF-8-water", "ZIF-67-water" and "ZIF-71-water" systems display a shock-absorber behaviour. A very important hysteresis for ZIF-71 and a slight difference between the first intrusion-extrusion cycle and the following ones for ZIF-67 were observed. ZIF-8 (SOD) with zinc cation and ZIF-67 (SOD) with cobalt cation display similar intrusion pressures. For ZIF-71 (RHO) material, the stored energy is more than doubled compared to ZIF-8 and ZIF-67 (SOD). This might be related to the topology. No water intrusion was observed after three water intrusion-extrusion cycles, for the ZIF-90 (SOD), Zn(dcim)2-SALE (SOD), ZIF-7 (SOD) and ZIF-11 (RHO) materials. This is explained in term of hydrophilic feature as well as topology and linker effects.

  20. Simulation of sea water intrusion in coastal aquifers: Some typical responses

    Indian Academy of Sciences (India)

    Amlan Das; Bithin Datta

    2001-08-01

    Seawater intrusion in coastal aquifers is generally three dimensional (3-D) in nature. In the literature, there is a general lack of reported results on 3-D simulations. This paper presents some typical example simulations of 3-D seawater intrusion process for a specified hypothetical study area. The simulation results presented in this paper are based on the density-dependent miscible flow and transport modelling approach for simulation of seawater intrusion in coastal aquifers. A nonlinear optimization-based simulation methodology was used in this study. Various steady state simulations are performed for a specified study area. Response evaluations consider the effects of vertical recharge on seawater intrusion, effects of boundary conditions, and effects of spatially varying pumping from the aquifer. The 3-D simulations demonstrate the viability of using a planned strategy of spatially varying withdrawals from the aquifer to manage seawater intrusion. It is demonstrated that series of pumps near the ocean-face boundary induce a hydraulic head distribution that can be effectively used for controlling seawater intrusion.

  1. On-line detection of Escherichia coli intrusion in a pilot-scale drinking water distribution system.

    Science.gov (United States)

    Ikonen, Jenni; Pitkänen, Tarja; Kosse, Pascal; Ciszek, Robert; Kolehmainen, Mikko; Miettinen, Ilkka T

    2017-08-01

    Improvements in microbial drinking water quality monitoring are needed for the better control of drinking water distribution systems and for public health protection. Conventional water quality monitoring programmes are not always able to detect a microbial contamination of drinking water. In the drinking water production chain, in addition to the vulnerability of source waters, the distribution networks are prone to contamination. In this study, a pilot-scale drinking-water distribution network with an on-line monitoring system was utilized for detecting bacterial intrusion. During the experimental Escherichia coli intrusions, the contaminant was measured by applying a set of on-line sensors for electric conductivity (EC), pH, temperature (T), turbidity, UV-absorbance at 254 nm (UVAS SC) and with a device for particle counting. Monitored parameters were compared with the measured E. coli counts using the integral calculations of the detected peaks. EC measurement gave the strongest signal compared with the measured baseline during the E. coli intrusion. Integral calculations showed that the peaks in the EC, pH, T, turbidity and UVAS SC data were detected corresponding to the time predicted. However, the pH and temperature peaks detected were barely above the measured baseline and could easily be mixed with the background noise. The results indicate that on-line monitoring can be utilized for the rapid detection of microbial contaminants in the drinking water distribution system although the peak interpretation has to be performed carefully to avoid being mixed up with normal variations in the measurement data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Identification of saline water intrusion in part of Cauvery deltaic region, Tamil Nadu, Southern India: using GIS and VES methods

    Science.gov (United States)

    Gnanachandrasamy, G.; Ramkumar, T.; Venkatramanan, S.; Chung, S. Y.; Vasudevan, S.

    2016-06-01

    We use electrical resistivity data arrayed in a 2715 km2 region with 30 locations to identify the saline water intrusion zone in part of Cauvery deltaic region, offshore Eastern India. From this dataset we are able to derive information on groundwater quality, thickness of aquifer zone, structural and stratigraphic conditions relevant to groundwater conditions, and permeability of aquifer systems. A total of 30 vertical electrode soundings (VES) were carried out by Schlumberger electrode arrangement to indicate complete lithology of this region using curve matching techniques. The electrical soundings exhibited that H and HK type curves were suitable for 16 shallow locations, and QH, KQ, K, KH, QQ, and HA curves were fit for other location. Low resistivity values suggested that saline water intrusion occurred in this region. According to final GIS map, most of the region was severely affected by seawater intrusion due to the use of over-exploitation of groundwater.The deteriorated groundwater resources in this coastal region should raise environmental and health concerns.

  3. Consequences of CO2-rich water intrusion into the Critical Zone

    Science.gov (United States)

    Gal, Frédérick; Lions, Julie

    2017-04-01

    From a geochemical point of view, the sensitivity of the Critical Zone to hazards is not only linked to its proximity to the surface. It may also be linked to - albeit less common - intrusion of upward migrating fluids. One of the hazard scenarios to observe these pathways in surface environments is the occurrence of CO2-rich fluid leakage from deeper horizons and especially leakage from reservoir in the case of underground storage such as Carbon Storage applications. Much effort is done to prevent this risk but it necessary to consider the mitigation of this leak to insure safe storage. Numerous active or planned CO2 storage sites belong to large sedimentary basins. In that perspective, a CO2 injection has been performed in a multi-layered - carbonated aquifer (Beauce aquifer) from the Paris basin as this basin has been considered for such applications. The aquifer mineralogy of the targeted site is dominated by calcite (95 to 98%) with traces of quartz and clay minerals. Around 10,000 liters of CO2 were injected at 50 m depth during a series of gaseous pulsed injections for 5 days. After 3 days of incubation in the aquifer, the groundwater was pumped during 5 days allowing the recovery of 140 m3 of backward water. Physico-chemical parameters, major and trace elements concentrations and dissolved CO2 concentrations were monitored to evaluate water-rock interactions occurring within the aquifer and impacts onto water quality. Main changes that were observed during the CO2 release are in good agreement with results from previous experiments performed worldwide. A strong decrease of the pH value (2 units), a rise of the electrical conductivity (2 fold) and changes in the redox conditions (from oxidising to less oxidising) are monitored few hours after the initiation of the pumping. The dissolution of CO2 induces a drop of pH that favours water-rock interaction processes. The kinetic of reactions appears to be dominated by the dissolution of carbonate, mainly calcite

  4. A quantitative investigation on sea water intrusions and its related remediation strategy in the Penghu Island, Taiwan

    Science.gov (United States)

    Lee, Jhe-Wei; Chou, Ssu-Yu; Lo, Wei-Cheng

    2017-04-01

    Penghu islands is one of Taiwan's three major volcanic group, with basalt from cooled lava forming major rocks of each island. This research was undertaken to investigate the current stage of groundwater hydrology, usage, and salinization in Penghu. We evaluated, in qualitative and quantitative manners, the potential causes of groundwater salinization based on our test results, which provides useful information to build the geological model for numerical studies in Penghu. We applied MODFLOW and its sub-mode MT3DMS to simulate the groundwater level and seawater intrusion in Penghu, and proposed the remediation strategy for groundwater resource protection. According to the information collected as well as the results obtained, there are three issues of groundwater salinization that should be well addressed in Penghu. The first is to characterize the mechanism of groundwater salinization in confine and unconfined aquifers, respectively; the second is to identify the attribute of groundwater salinization; the third is to delineate the spatial distribution of the groundwater control zone and the area of groundwater salinization. These issues were solved through two different aspects in this research: field investigation and groundwater modeling. In the field investigation, we sampled 15 wells three times to examine groundwater quality. Our analysis indicated that the potential causes for groundwater salinization can be essentially categorized into three parts: (1) seawater intrusion, (2) the existence of residual ancient brine water, and (3) the calcium ion and magnesium ion released from stratum. To obtain better understanding of the interchange between rain and groundwater, we also performed hydrogen and oxygen isotopic analysis additionally, which is beneficial to assess the recharge source of the groundwater subarea. In reference to remediation strategy, recharge into aquifer is not recommended since there is no sufficient surface water storage, and therefore a

  5. DETECTION OF DRY INTRUSION ON WATER VAPOR IMAGES OVER CENTRAL EUROPE – JUNE 2010 TO SEPTEMBER 2011

    Directory of Open Access Journals (Sweden)

    J. Novotny

    2016-06-01

    Full Text Available The knowledge of evaluation of the intensity of cyclogenesis which could be connected with the weather having a significant impact on Earth’s surface is quite useful. If, as one of the basic assumptions, the existence of connection between dry intrusions, dry bands, tropopause height and warm dark areas distribution on water vapor images (WV images is considered, it is possible to set up a method of detecting dry intrusions on searching and tracking areas with higher brightness temperature compared with the surrounding environment. This paper covers the period between June 2010 and September 2011 over Central Europe. The ISIS method (Instrument de Suivi dans I’Imagerie satellitaire, originally developed for detection of cold cloud tops, was used as an initial ideological point. Subsequently, this method was modified by Michel and Bouttier for usage on WV images. Some of the applied criteria and parameters were chosen with reference to the results published by Michel and Bouttier as well as by Novotny. The procedure can be divided into two steps: detection of warm areas and their tracking. Cases of detection of areas not evidently connected with dry intrusions can be solved by filtering off based on the connection between detected warm areas to the cyclonic side of jet streams and significant lowering of the tropopause.

  6. The effect of sea-water intrusion due to the large scale construction in a coastal region

    Science.gov (United States)

    Hyun, S.; Jin, S.; Woo, N. C.; Lee, J.; Lee, H.; Kim, Y.

    2010-12-01

    This study was carried out for estimating the seawater intrusion at the disturbed aquifer by a large scale construction when building a power plant in a coastal region, located in southeastern part of the Korean peninsula. Groundwater sampling and vertical profiling of electrical conductivity(EC) for 8 monitoring wells were carried. EC profiling results shows that maximum EC for PW-5, 6 and 7 is over 40 mS/cm, for PZ-1, 3, 4 and 8 is 18.76, 4.46, 26.16, 21.42 mS/cm and for PZ-2 is 0.79 mS/cm,respectively. Chemical composition of water samples shows that water types of Na-Cl for PZ-5, 6, and 7 (excavated and backfilled area), Na-Cl-SO4 for PZ-4 and PZ-8, Na-Ca-Mg-Cl for PZ-1, Ca-Na-SO4-Cl for PZ-2, and Mg-Ca-Na-SO4 for PZ-3. In addition, the bivariate plot of SO4/Cl(meq ratios) and SO4(mmol/L) indicates that PZ-4, 5, 6, 7 and 8 appear to be seawater, PZ-1 is located at mixing zone between freshwater and seawater, and PZ-2 is freshwater. However, based on the high SO42- level and (HCO3-/Sum anions} ratio less than 0.8, groundwater at PZ-3 seems to show the gypsum dissolution. The gypsum dissolution was attributed to the effect of sea-water intrusion on ageing of lean concrete that was used for backfill around the PZ-3. Key words : large scale construction, EC profiling, hydrochemistry, sea-water intrusion, concrete ageing Acknowledgement This study has been carried out under the Nuclear R&D Program [No. 2010-0001070] supported by the Ministry of Education, Science and Technology, Republic of Korea.

  7. Simultaneous lidar observations of the water vapor and ozone signatures of a stratospheric intrusion during the MOHAVE-2009 campaign

    Science.gov (United States)

    Leblanc, T.; McDermid, I. S.; Pérot, K.

    2010-12-01

    Ozone and water vapor signatures of a stratospheric intrusion were simultaneously observed by the Jet Propulsion Laboratory lidars located at Table Mountain Facility, California (TMF, 34.4N, 117.7W) during the Measurements of Humidity in the Atmosphere and Validation Experiments (MOHAVE-2009) campaign in October 2009. These observations are placed in the context of the meridional displacement and folding of the tropopause, and resulting contrast in the properties of the air masses sampled by lidar. The lidar observations are supported by model data, specifically potential vorticity fields advected by the high-resolution transport model MIMOSA, and by 10-day backward isentropic trajectories. The ozone and water vapor anomalies measured by lidar were largely anti-correlated, and consistent with the assumption of a wet and ozone-poor subtropical upper troposphere, and a dry and ozone-rich extra-tropical lowermost stratosphere. However, it is shown that this anti-correlation relation collapsed just after the stratospheric intrusion event of October 20, suggesting mixed air embedded along the subtropical jet stream and sampled by lidar during its displacement south of TMF (tropopause fold). The ozone-PV expected positive correlation relation held strongly throughout the measurement period, including when a lower polar stratospheric filament passed over TMF just after the stratospheric intrusion. The numerous highly-correlated signatures observed during this event demonstrate the strong capability of the water vapor and ozone lidars at TMF, and provide new confidence in the future detection by lidar of long-term variability of water vapor and ozone in the Upper Troposphere-Lower Stratosphere (UTLS).

  8. Phytoplankton response to intrusions of slope water on the West Florida Shelf: Models and observations

    Science.gov (United States)

    Walsh, John J.; Weisberg, Robert H.; Dieterle, Dwight A.; He, Ruoying; Darrow, Brian P.; Jolliff, Jason K.; Lester, Kristen M.; Vargo, Gabriel A.; Kirkpatrick, Gary J.; Fanning, Kent A.; Sutton, Tracey T.; Jochens, Ann E.; Biggs, Douglas C.; Nababan, Bisman; Hu, Chuanmin; Muller-Karger, Frank E.

    2003-06-01

    Previous hypotheses had suggested that upwelled intrusions of nutrient-rich Gulf of Mexico slope water onto the West Florida Shelf (WFS) led to formation of red tides of Karenia brevis. However, coupled biophysical models of (1) wind- and buoyancy-driven circulation, (2) three phytoplankton groups (diatoms, K. brevis, and microflagellates), (3) these slope water supplies of nitrate and silicate, and (4) selective grazing stress by copepods and protozoans found that diatoms won in one 1998 case of no light limitation by colored dissolved organic matter (CDOM). The diatoms lost to K. brevis during another CDOM case of the models. In the real world, field data confirmed that diatoms were indeed the dominant phytoplankton after massive upwelling in 1998, when only a small red tide of K. brevis was observed. Over a 7-month period of the CDOM-free scenario the simulated total primary production of the phytoplankton community was ˜1.8 g C m-2 d-1 along the 40-m isobath of the northern WFS, with the largest accumulation of biomass on the Florida Middle Ground (FMG). Despite such photosynthesis, these models of the WFS yielded a net source of CO2 to the atmosphere during spring and summer and suggested a small sink in the fall. With diatom losses of 90% of their daily carbon fixation to herbivores the simulation supported earlier impressions of a short, diatom-based food web on the FMG, where organic carbon content of the surficial sediments is tenfold those of the surrounding seabeds. Farther south, the simulated near-bottom pools of ammonium were highest in summer, when silicon regeneration was minimal, leading to temporary Si limitation of the diatoms. Termination of these upwelled pulses of production by diatoms and nonsiliceous microflagellates mainly resulted from nitrate exhaustion in the model, however, mimicking most del15PON observations in the field. Yet, the CDOM-free case of the models failed to replicate the observed small red tide in December 1998, tagged

  9. Mapping saline water intrusion into the coastal aquifer with geophysical and geochemical techniques: the University of Lagos campus case (Nigeria).

    Science.gov (United States)

    Ayolabi, Elijah A; Folorunso, Adetayo F; Odukoya, Abiodun M; Adeniran, Adelere E

    2013-01-01

    Saltwater intrusion into the coastal aquifer, a phenomenon brought by the flow of seawater into freshwater aquifers originally caused by groundwater extraction near the coast, has long been recognised as a major concern around the world. In this study, we employed geophysical and geochemical techniques to map and provide evidences that the coastal aquifers in the study area have been intruded by saltwater from the adjacent Lagos lagoon. The resistivity data were acquired with an electrode spacing (a) that vary between 1.6 to 8 m, and expansion factor n of 30. The depth inverted models obtained from inversion of the fifteen resistivity data obtained in the area revealed significant impact of the lagoon water on the aquifers indicated as low resistivity usually below 7 Ωm. A combination of four different electrode arrays - Schlumberger, Wenner, Dipole-dipole and pole-dipole, with at least three deployed at each site ( except for three traverses - traverses 13, 14 and 15), yield better horizontal and vertical resolution, having depth range of 36-226 m with 1.6-8 m electrode spacing used. The delineated geoelectric layers were juxtaposed with logs from both boreholes located within the campus. Evidence from geochemical study of borehole and the lagoon water samples corroborated the ERT result. Progressive decrease in total dissolved solute (TDS) and electrical conductivity (EC) from the lagoon to the coastal aquifer buttresses gradual encroachment of the inland aquifers by the intruding lagoon water. In addition, similar trend was observed in heavy metal distribution Pollution Index (PI) plot suggesting possible underground flow of water from the lagoon to the aquifers. From this study, we deduced that excessive groundwater extraction and possibly the reduction of groundwater gradients which allows saline-water to displace fresh water in the aquifer of the investigated area are responsible for the saline water intrusion observed.

  10. Water intrusions and particle signatures in the Black Sea: a Biogeochemical-Argo float investigation

    Science.gov (United States)

    Stanev, Emil Vassilev; Grayek, Sebastian; Claustre, Hervé; Schmechtig, Chaterine; Poteau, Antoine

    2017-09-01

    Continuous observations during 3 years with a vertical resolution of 1 dbar from two Bio-Argo floats in the Black Sea that were equipped with oxygen optodes, chlorophyll fluorometers, and backscattering sensors are analyzed. The particle backscattering coefficient, b bp provides a proxy for the concentration of suspended particles. The observations clearly identify thermal and b bp intrusions down to 700-800 m in the Bosporus inflow area. In this area, b bp is more than five times larger than elsewhere, which could indicate bacterial abundance and possible biological involvement in the precipitation of Mn-containing particles. The b bp anomalies become much shallower than the temperature anomalies with increasing distance to the east of the strait. Their maxima are located between the onset of the suboxic zone and the upper part of the anoxic layer. Unlike well-known intrusions that are caused by inflow, open ocean intrusions are shallower and often characterized by multiple layers of backscatter maxima with thicknesses of only 15-20 m. The ratio between backscattering coefficients measured at two wavelengths, which gives a proxy for particle size, shows that the relative amount of larger size particles in the anoxic layer increases with depth. The particle concentrations and their size distribution display different vertical variability, which indicates the complex transformation of biological matter. The lower concentration of particles and lower chlorophyll-a during the extremely warm 2016 reveals an overall positive correlation between the two properties. The trends in the particle backscattering coefficient in the suboxic zone during 2013-2016 could indirectly reveal a biogeochemical response to temperature changes.

  11. Analysis of water vapor LIDAR measurements during the MAP campaign: evidence of sub-structures of stratospheric intrusions

    Science.gov (United States)

    D'Aulerio, P.; Fierli, F.; Congeduti, F.; Redaelli, G.

    2005-06-01

    This paper presents two case studies of transport of dry air in the free troposphere measured by a ground based Raman LIDAR in the Northern-Italy, during the Mesoscale Alpine Programme (MAP). Two observations characterized by the presence of anomalously dry layers, below 6 km height, were analyzed using Lagrangian techniques. These events are related to upper-tropospheric, high Potential Vorticity (PV) streamers crossing the Alpine region. These are interpreted as small-scale features of stratospheric intrusions associated with the PV ridge during its phase of dissipation. One of the measurements also shows the presence of two distinct dehydrated structures associated with the same event. The water vapor concentration also suggests dilution processes of dry stratospheric air in the troposphere. Lagrangian simulations allowed to successfully reproduce the observed water vapor distribution and the air parcel histories confirmed the stratospheric origin of the dry layers.

  12. Global assessment of coastal aquifer state and its vulnerability respect to Sea Water Intrusion. Application to several Mediterranean Coastal Aquifers.

    Science.gov (United States)

    Baena, Leticia; Pulido-Velazquez, David; Renau-Pruñonosa, Arianna; Morell, Ignacio

    2017-04-01

    In this research we propose a method for a global assessment of coastal aquifer state and its vulnerability to Sea Water Intrusion (SWI). It is based on two indices, the MART index, which summarize the global significance of the SWI phenomenon, and the L_GALDIT for a lumped assessment of the vulnerability to SWI. Both of them can be useful as a tool to assess coastal groundwater bodies in risk of not achieving good status in accordance with the Water Framework Directive (WFD, 2000) and to identify possible management alternative to reduce existing impacts. They can be obtained even from a reduced number of data (in the MART case only depend on the geometry and available aquifer state data) with simple calculations, which have been implemented in a general GIS tool that can be easily applied to other case studies. The MART index in an aquifer is related with the total mass of chloride in the aquifer due to sea water intrusion and can be obtained by simple linear operations of volume and concentrations that can be deduced from a schematic conceptual cross-section approach (orthogonal to the shore line) defined to summarize the intrusion volume in the aquifer. At a certain historical time, this representative aquifer cross-section can be defined in a systhematic way from the aquifer geometry, the specific yield, and the hydraulic head and chloride concentration fields that can be deduced from the available information by using appropriate interpolation methods. Following the proposed procedure we will finally obtain a summary of the historical significance of the SWI in an aquifer at different spatial resolution: 3D salinity concentration maps, 2D representative conceptual cross-section of intrusion and the MART lumped significance index. The historical evolution of the MART can be employed to perform a global assessment of the resilience and trends of global significance of the SWI in an aquifer. It can be useful to compare the significance of intrusion problems in

  13. Intrusion dynamics of particle plumes in stratified water with weak crossflow: Application to deep ocean blowouts

    Science.gov (United States)

    Wang, Dayang; Adams, E. Eric

    2016-06-01

    We present an experimental study of particle plumes in ambient stratification and a mild current. In an inverted framework, the results describe the fate of oil droplets released from a deep ocean blowout. A continuous stream of dense glass beads was released from a carriage towed in a salt-stratified tank. Nondimensional particle slip velocity UN ranged from 0.1 to 1.9, and particles with UN ≤ 0.5 were observed to enter the intrusion layer. The spatial distributions of beads, collected on a bottom sled towed with the source, present a Gaussian distribution in the transverse direction and a skewed distribution in the along-current direction. Dimensions of the distributions increase with decreasing UN. The spreading relations can be used as input to far-field models describing subsequent transport of particles or, in an inverted framework, oil droplets. The average particle settling velocity, Uave, was found to exceed the individual particle slip velocity, Us, which is attributed to the initial plume velocity near the point of release. Additionally, smaller particles exhibit a "group" or "secondary plume" effect as they exit the intrusion as a swarm. The secondary effect becomes more prominent as UN decreases, and might help explain observations from the 2000 Deep Spill field experiment where oil was found to surface more rapidly than predicted based on Us. An analytical model predicting the particle deposition patterns was validated against experimental measurements, and used to estimate near-field oil transport under the Deepwater Horizon spill conditions, with/without chemical dispersants.

  14. Coupled human-water system dynamics of saltwater intrusion in the low coastal plain of the Po River, Ravenna, Italy

    Science.gov (United States)

    Lauriola, Ilaria; Ciriello, Valentina; Antonellini, Marco; Pande, Saket

    2017-04-01

    Human activities affect the whole hydrological cycle with possible severe consequences on ecosystem services. Human-water interaction follows complex dynamics that can't be addressed only through the analysis of water withdrawals and contamination processes. As such, comprehensive analysis strategies based on a socio-hydrology approach may allow to deeply understand the co-evolution of human and water systems. Here, we focus on the low coastal plain of the Po river in the south of Ravenna (Italy), which is adjacent to the North Adriatic sea. In particular, our study regards a basin characterized by a land reclamation drainage system, given the low topography which reaches in some places 1 m below sea level. In this area, the thin phreatic coastal aquifer is affected by a relevant salinization process and characterized by the presence of valuable water-dependent ecosystems such as pine forests and wetlands. Groundwater salinization is mainly caused by seawater intrusion due to the hydraulic gradient landwards that is enhanced by land subsidence, land use and drainage allowing for agriculture and settlements. Such a complex scenario involves environmental, social and economic interests. We study the intricate system of relationships occurring between a set of socio-hydrological state variables of interest based on the dynamic analysis of land use changes in the study area that mainly affect groundwater recharge and the availability of freshwater for ecosystem and agriculture activities.

  15. Delineation of salt water intrusion through use of electromagnetic-induction logging: A case study in Southern Manhattan Island, New York

    Science.gov (United States)

    Stumm, Frederick; Como, Michael D.

    2017-01-01

    Groundwater with chloride concentrations up to 15,000 mg/L has intruded the freshwater aquifer underlying southern Manhattan Island, New York. Historical (1940–1950) chloride concentration data of glacial aquifer wells in the study area indicate the presence of four wedges of saltwater intrusion that may have been caused by industrial pumpage. The limited recharge capability of the aquifer, due to impervious surfaces and the 22.7 million liters per day (mld) of reported industrial pumpage early in the 20th Century was probably the cause for the saltwater intrusion and the persistence of the historical saltwater intrusion wedges over time. Recent drilling of wells provided new information on the hydrogeology and extent of saltwater intrusion of the glacial aquifer overlying bedrock. The new observation wells provided ground-water level, chloride concentration, hydraulic conductivity, and borehole geophysical data of the glacial aquifer. The glacial sediments range in thickness from less than 0.3 m to more than 76.2 m within the study area. A linear relation between Electromagnetic-induction (EM) conductivity log response and measured chloride concentration was determined. Using this relation, chloride concentration was estimated in parts of the glacial aquifer where sampling was not possible. EM logging is an effective tool to monitor changes in saltwater intrusion wedges.

  16. The vertical structure of ozone and water vapor profiles in Lhasa within Asia summer monsoon anticyclone during the stratospheric intrusion

    Science.gov (United States)

    Li, Dan; Vogel, Bärbel; Bian, Jianchun; Müller, Rolf; Günther, Gebhard; Bai, Zhixuan; Li, Qian; Fan, Qiujun; Zhang, Jinqiang

    2017-04-01

    A stratospheric intrusion process occurred over the southeastern side of the Asia summer monsoon (ASM) region is investigated using the balloon-borne measurements of ozone and water vapor during 18-20 August 2013. Data from Lhasa (29.66° N, 91.14° E, above sea level (asl.) 3,650 m) show that the positive relative change of the ozone mixing ratios in the tropopause layer attained to 90 % on 19 and 20 August. The backward trajectory calculation from CLaMS model and the satellite data from the ozone monitoring instrument (OMI) and the atmospheric infrared sounder (AIRS) indicate that the (stratospheric) air parcels intruded (originated) from the Northeast Asia to the southeastern edge of the ASM anticyclone. Meanwhile, typhoon Utor occurred over the sourtheastern edge of the ASM and lasted from 8 to 18 August 2013. The convection associated with Utor uplifted air with low ozone from the Western Pacific to the middle/upper troposphere. Air parcels with high ozone from the high latitude and with low ozone from the Western Pacific met at the sourtheastern side of the ASM and then transported westward to Lhasa over long-distances (˜2,000 km). In addition, the laminated identification method is used to identify the laminae structure of the ozone and water vapor profiles from the middle troposphere to the lower stratosphere in Lhasa, confirming the role of the dynamic disturbance (e.g., Rossby and gravity wave)

  17. Enrichment of fluoride in groundwater under the impact of saline water intrusion at the salt lake area of Yuncheng basin, northern China

    Science.gov (United States)

    Gao, Xubo; Wang, Yanxin; Li, Yilian; Guo, Qinghai

    2007-12-01

    Long-term intake of high-fluoride groundwater causes endemic fluorosis. This study, for the first time, discovered that the salt lake water intrusion into neighboring shallow aquifers might result in elevation of fluoride content of the groundwater. Two cross-sections along the groundwater flow paths were selected to study the geochemical processes controlling fluoride concentration in Yuncheng basin, northern China. There are two major reasons for the observed elevation of fluoride content: one is the direct contribution of the saline water; the other is the undersaturation of the groundwater with respect to fluorite due to salt water intrusion, which appears to be more important reason. The processes of the fluorine activity reduction and the change of Na/Ca ratio in groundwater induced by the intrusion of saline water favor further dissolution of fluorine-bearing mineral, and it was modeled using PHREEQC. With the increase in Na concentration (by adding NaCl or Na2SO4 as Na source, calcium content kept invariable), the increase of NaF concentration was rapid at first and then became slower; and the concentrations of HF, HF{2/-}, CaF+, and MgF+ were continuously decreasing. The geochemical conditions in the study area are advantageous to the complexation of F- with Na+ and the decline of saturation index of CaF2, regardless of the water type (Cl-Na or SO4-Na type water).

  18. A system dynamics mode-based exploratory analysis of salt water intrusion in coastal aquifers

    NARCIS (Netherlands)

    Kwakkel, J.H.; Slinger, J.H.

    2012-01-01

    Coastal communities dependent upon groundwater resources for drinking water and irrigation are vulnerable to salinization of the groundwater reserve. The increasing uncertainty associated with changing climatic conditions, population and economic development, and technological advances poses signifi

  19. SWIBANGLA: Managing salt water intrusion impacts in coastal groundwater systems of Bangladesh

    NARCIS (Netherlands)

    Faneca Sànchez, Marta; Bashar, Khairul; Janssen, Gijs; Vogels, Marjolein; Snel, Jan; Zhou, Yangxiao; Stuurman, Roelof J.; Oude Essink, Gualbert

    2015-01-01

    Bangladesh is densely populated and it is expected that the population increases significantly in the coming decade, up to 60% more by 2050 according to IIASA (2013). Demand for drinking water will increase accordingly. These developments may cause significant changes in the hydrological system, e.g

  20. Seawater Intrusion Impacts on the Water Quality of the Groundwater on theNorthwest Coast of Oman.

    Science.gov (United States)

    Ahmed, Abdelkader T; Askri, Brahim

    2016-08-01

    The groundwater aquifer in the coastal region of the northwest of Oman has been used extensively since the early 1980s for agricultural, industrial and municipal purposes. The over pumping of this reservoir has led to the intrusion of seawater and therefore to the deterioration of the groundwater quality. In this study, an investigation was carried out in the southern part of this region to identify the quality of groundwater, to understand the main sources of groundwater mineralisation, and to check the suitability of groundwater for drinking and irrigation. The spatial distributions and temporal variations of groundwater level and electrical conductivity were studied for the period from 1982 to 2005 using data collected from 225 wells. In addition, groundwater samples were collected recently in 2012 from eight wells and analysed for pH, EC, and major ions to understand the sources of dissolved ions and assess the chemical quality of the groundwater. The study area was divided into two strips parallel to the coastline, A and B, located in the discharge and recharge parts of the aquifer, respectively. Results showed a significant increase in the degree of water mineralisation in the direction of south to north following the regional flow direction. Results showed also that the groundwater in the last area could be used for irrigation with little danger of exchangeable sodium while this aquifer is unsuitable for irrigation in the discharge area because it presents a very high salinity hazard.

  1. Influence of ambient water intrusion on coral reef acidification in the Chuuk lagoon, located in the coral-rich western Pacific Ocean

    Science.gov (United States)

    Ko, Young Ho; Lee, Kitack; Noh, Jae Hoon; Lee, Charity M.; Kleypas, Joan A.; Jeong, Hae Jin; Kim, Kwang Young

    2016-04-01

    Weekly carbonate chemistry condition data recorded between 2008 and 2014 in the Chuuk lagoon (7.3°N and 151.5°E) of the Federated States of Micronesia, located in the western Pacific Ocean, were analyzed. The results showed that, during periods of weak intrusion of ambient seawater from the surrounding open ocean, two internal biological processes (calcification and respiration) reinforced each other and together lowered the pH of the reef water for extended periods, ranging from a few to several months. The analysis indicated that reduced intrusion of ambient water is associated with periods of low wind speeds. Such conditions increase the residence time of reef water, thus promoting acidification by respiration and calcification. This phenomenon likely affects many other areas of the coral-rich western Pacific Ocean, which contains 50% of global coral reefs and in which the degree of ambient water intrusion into the atolls has been shown to be closely associated with the El Niño-Southern Oscillation-induced wind speed change.

  2. Real-time 4D ERT monitoring of river water intrusion into a former nuclear disposal site using a transient warping-mesh water table boundary (Invited)

    Science.gov (United States)

    Johnson, T.; Hammond, G. E.; Versteeg, R. J.; Zachara, J. M.

    2013-12-01

    The Hanford 300 Area, located adjacent to the Columbia River in south-central Washington, USA, is the site of former research and uranium fuel rod fabrication facilities. Waste disposal practices at site included discharging between 33 and 59 metric tons of uranium over a 40 year period into shallow infiltration galleries, resulting in persistent uranium contamination within the vadose and saturated zones. Uranium transport from the vadose zone to the saturated zone is intimately linked with water table fluctuations and river water intrusion driven by upstream dam operations. As river stage increases, the water table rises into the vadose zone and mobilizes contaminated pore water. At the same time, river water moves inland into the aquifer, and river water chemistry facilitates further mobilization by enabling uranium desorption from contaminated sediments. As river stage decreases, flow moves toward the river, ultimately discharging contaminated water at the river bed. River water specific conductance at the 300 Area varies around 0.018 S/m whereas groundwater specific conductance varies around 0.043 S/m. This contrast provides the opportunity to monitor groundwater/river water interaction by imaging changes in bulk conductivity within the saturated zone using time-lapse electrical resistivity tomography. Previous efforts have demonstrated this capability, but have also shown that disconnecting regularization constraints at the water table is critical for obtaining meaningful time-lapse images. Because the water table moves with time, the regularization constraints must also be transient to accommodate the water table boundary. This was previously accomplished with 2D time-lapse ERT imaging by using a finely discretized computational mesh within the water table interval, enabling a relatively smooth water table to be defined without modifying the mesh. However, in 3D this approach requires a computational mesh with an untenable number of elements. In order to

  3. KERENTANAN PENYUSUPAN AIR LAUT DI PESISIR UTARA PULAU TERNATE (Vulnerability of Sea Water Intrusion in Northern Coastal of Ternate Island

    Directory of Open Access Journals (Sweden)

    Rahim Achmad

    2016-07-01

    Full Text Available ABSTRAK Penelitian ini dilakukan di wilayah pesisir bagian utara Pulau Ternate, dengan tujuan mengetahui kedalaman batas kontak airtanah dengan air laut dan menganalisis akuifer serta cara pengambilan airtanah sehingga tidak terjadi penyusupan air laut ke dalam tubuh airtanah. Sampel air sumur diukur untuk mengetahui kadar salinitas dan daya hantar listrik (DHL. Kedalaman batas kontak airtanah dengan air laut dukur dengan menggunakan metode geolistrik. Hasil pengukuran DHL dan salinitas airtanah di wilayah pesisir utara menunjukkan, terdapat penyusupan air laut di Desa Tobolo dan Sulamadaha, dengan rentang nilai masing-masing antara 0,5-3,3 mS/cm dan 0,2-1,7 ppt. Hasil pengukuran geolistrik menunjukkan batas kontak airtanah dengan air laut rata-rata antara 12-15 m dari permukaan. Nilai resistivitas air laut berkisar antara 0,01-20 Ωm. Hasil penelitian ini memberikan peringatan untuk tidak melakukan pengeboran sumur di wilayah pesisir. Sebagai contoh kasus, pengeboran sumur hingga 80 m dengan jarak sekitar 250 m dari garis pantai di Desa Takome, di mana batas kontak airtanah dengan air laut pada kedalaman 15 m. Pengukuran nilai DHL dan salinatas air dari sumur ini menunjukkan masing-masing 6,1 mS/cm dan 3,3 ppt. Nilai ini menunjukkan kedalaman sumur bor telah melewati zona pencampuran antara airtanah dengan air laut (interface.   ABSTRACT This research was conducted in the coastal areas of northern part of Ternate island, in order to know the depth of interface and to analyze the aquifers and to avoid seawater intrusion caused of groundwater extraction. Well water samples were measured to determine levels of salinity and DHL. The depth of interface was measured using geoelectric method. The results of electrical conductivity (EC and salinity of groundwater measurement in the northern coastal area showed that, there is infiltration of sea water in Tobolo and Sulamadaha. The EC and salinity values ranging between 0.5-3.3 mS/cm and 0.2-1.7 ppt

  4. Intrusion of Fukushima-derived radiocaesium into subsurface water due to formation of mode waters in the North Pacific

    Science.gov (United States)

    Kaeriyama, Hideki; Shimizu, Yugo; Setou, Takashi; Kumamoto, Yuichiro; Okazaki, Makoto; Ambe, Daisuke; Ono, Tsuneo

    2016-02-01

    The Fukushima Dai-ichi Nuclear Power Plant accident in March 2011 released radiocaesium (137Cs and 134Cs) into the North Pacific Ocean. Meridional transects of the vertical distribution of radiocaesium in seawater were measured along 147 °E and 155 °E in October-November 2012, 19 months after the accident. These measurements revealed subsurface peaks in radiocaesium concentrations at locations corresponding to two mode waters, Subtropical Mode Water and Central Mode Water. Mode water is a layer of almost vertically homogeneous water found over a large geographical area. Here we show that repeated formation of mode water during the two winter seasons after the Fukushima accident and subsequent outcropping into surface water transported radiocaesium downward and southward to subtropical regions of the North Pacific. The total amount of Fukushima-derived 134Cs within Subtropical Mode Water, decay-corrected to April 2011, was estimated to be 4.2 ± 1.1 PBq in October-November 2012. This amount of 134Cs corresponds to 22-28% of the total amount of 134Cs released to the Pacific Ocean.

  5. Integrated approach for demarcating subsurface pollution and saline water intrusion zones in SIPCOT area: a case study from Cuddalore in Southern India.

    Science.gov (United States)

    Sankaran, S; Sonkamble, S; Krishnakumar, K; Mondal, N C

    2012-08-01

    This paper deals with a systematic hydrogeological, geophysical, and hydrochemical investigations carried out in SIPCOT area in Southern India to demarcate groundwater pollution and saline intrusion through Uppanar River, which flows parallel to sea coast with high salinity (average TDS 28, 870 mg/l) due to back waters as well as discharge of industrial and domestic effluents. Hydrogeological and geophysical investigations comprising topographic survey, self-potential, multi-electrode resistivity imaging, and water quality monitoring were found the extent of saline water intrusion in the south and pockets of subsurface pollution in the north of the study area. Since the area is beset with highly permeable unconfined quaternary alluvium forming potential aquifer at shallow depth, long-term excessive pumping and influence of the River have led to lowering of the water table and degradation of water quality through increased salinity there by generating reversal of hydraulic gradient in the south. The improper management of industrial wastes and left over chemicals by closed industries has led surface and subsurface pollution in the north of the study area.

  6. Effects of seasonal change and seawater intrusion on water quality for drinking and irrigation purposes, in coastal aquifers of Dar es Salaam, Tanzania

    Science.gov (United States)

    Sappa, Giuseppe; Ergul, Sibel; Ferranti, Flavia; Sweya, Lukuba Ngalya; Luciani, Giulia

    2015-05-01

    Groundwater is the major source to meet domestic, industrial and agricultural needs in the city of Dar es Salaam, Tanzania. However, population growth, increasing urbanization, industrialization and tourism, and climatic changes have caused an intensive exploitation of groundwater resources leading the aquifers become more vulnerable to seawater intrusion. The aim of this study is to examine the variations of groundwater chemistry (as resulting from natural and anthropogenic inputs) depending on seasonal changes, in order to evaluate water quality for drinking and irrigation purposes. Physical and chemical data come from the analysis of groundwater samples, collected from 72 wells, used for the evaluation of water quality parameters, during a year of monitoring. Pattern diagrams, geochemical modeling techniques and Principal Component Analysis (PCA) have been used to identify the main factors influencing groundwater composition. Based on the hydrochemistry, the groundwater was classified into three types: (a) Na-Cl, (b) Ca-Cl, (c) mixed Ca-Na-HCO3-Cl (d) mixed Ca-Mg-Cl-SO4. The geochemical modeling results show that groundwater chemistry is mainly influenced by evaporation process, as it is suggested by the increase of Na and Cl ions concentrations. According to irrigation water quality assessment diagrams of USDA, most water samples from dry and rainy seasons, distributed in category C2-S1, C3-S1, C3-S2, C4-S2 highlighting medium to very high salinity hazard and low to medium sodium content class. PCA evidenced the role of seawater intrusion, evaporation process and anthropogenic pollution (i.e. high NO3 levels due to agricultural activities), as the major factors that influenced the water chemistry, and hence the water quality. Based on Pearson correlation matrix, the presence of high correlations (>0.8) among Na, Cl, Mg and SO4, in association with EC, were interpreted as the seawater intrusion effects. In this area groundwater quality is generally low, and

  7. Technology Review of Nondestructive Methods for Examination of Water Intrusion Areas on Hanford’s Double-Shell Waste Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, Michael L.; Pardini, Allan F.

    2008-05-09

    necessary to de-rate critical components. There are currently no tools that automatically convert the NDE data to formats compatible with structural analysis programs. While radiographic techniques still provide significant advantages in spatial resolution, non-ionizing techniques are still preferred. Radar imagining in the 1–5 GHz has become the most useful. Unfortunately the algorithms and underlying assumptions used in these reconstructions are proprietary, and it is not possible to assess the quality and limitations of the analytical methods used to generate the derived structural data. The hypothesis that water intrusion may contribute to potential rebar corrosion of the tank domes provided the primary guidance in reviewing and evaluating available NDE technologies. Of primary concern is the need to employ technologies that provide the best opportunity for visualizing the rebar and providing quantitative data that can be integrated into structural analysis efforts to better understand and quantify the structural capacity of the domes. The conclusion is that an imaging system capable of locating and quantifying the distribution and conditions of the cement, aggregate, and rebar will provide the most valuable baseline upon which to build a case for the integrity of the structure. If successful, such a system would fulfill the need to incorporate valuable data into current structural load capacity analysis.

  8. Hydrogeology, water quality, and saltwater intrusion in the Upper Floridan Aquifer in the offshore area near Hilton Head Island, South Carolina, and Tybee Island, Georgia, 1999-2002

    Science.gov (United States)

    Falls, W. Fred; Ransom, Camille; Landmeyer, James E.; Reuber, Eric J.; Edwards, Lucy E.

    2005-01-01

    To assess the hydrogeology, water quality, and the potential for saltwater intrusion in the offshore Upper Floridan aquifer, a scientific investigation was conducted near Tybee Island, Georgia, and Hilton Head Island, South Carolina. Four temporary wells were drilled at 7, 8, 10, and 15 miles to the northeast of Tybee Island, and one temporary well was drilled in Calibogue Sound west of Hilton Head Island. The Upper Floridan aquifer at the offshore and Calibogue sites includes the unconsolidated calcareous quartz sand, calcareous quartz sandstone, and sandy limestone of the Oligocene Lazaretto Creek and Tiger Leap Formations, and the limestone of the late Eocene Ocala Limestone and middle Avon Park Formation. At the 7-, 10-, and 15-mile sites, the upper confining unit between the Upper Floridan and surficial aquifers correlates to the Miocene Marks Head Formation. Paleochannel incisions have completely removed the upper confining unit at the Calibogue site and all but a 0.8-foot-thick interval of the confining unit at the 8-mile site, raising concern about the potential for saltwater intrusion through the paleochannel-fill sediments at these two sites. The paleochannel incisions at the Calibogue and 8-mile sites are filled with fine- and coarse-grained sediments, respectively. The hydrogeologic setting and the vertical hydraulic gradients at the 7- and 10-mile sites favored the absence of saltwater intrusion during predevelopment. After decades of onshore water use in Georgia and South Carolina, the 0-foot contour in the regional cone of depression of the Upper Floridan aquifer is estimated to have been at the general location of the 7- and 10-mile sites by the mid-1950s and at or past the 15-mile site by the 1980s. The upward vertical hydraulic gradient reversed, but the presence of more than 17 feet of upper confining unit impeded the downward movement of saltwater from the surficial aquifer to the Upper Floridan aquifer at the 7- and 10-mile sites. At the 10

  9. Petroleum Vapor Intrusion

    Science.gov (United States)

    One type of vapor intrusion is PVI, in which vapors from petroleum hydrocarbons such as gasoline, diesel, or jet fuel enter a building. Intrusion of contaminant vapors into indoor spaces is of concern.

  10. The impact of river water intrusion on trace metal cycling in karst aquifers: an example from the Floridan aquifer system at Madison Blue Spring, Florida

    Science.gov (United States)

    Brown, A. L.; Martin, J. B.; Screaton, E.; Spellman, P.; Gulley, J.

    2011-12-01

    Springs located adjacent to rivers can serve as recharge points for aquifers when allogenic runoff increases river stage above the hydraulic head of the spring, forcing river water into the spring vent. Depending on relative compositions of the recharged water and groundwater, the recharged river water could be a source of dissolved trace metals to the aquifer, could mobilize solid phases such as metal oxide coatings, or both. Whether metals are mobilized or precipitated should depend on changes in redox and pH conditions as dissolved oxygen and organic carbon react following intrusion of the river water. To assess how river intrusion events affect metal cycling in springs, we monitored a small recharge event in April 2011 into Madison Blue Spring, which discharges to the Withlacoochee River in north-central Florida. Madison Blue Spring is the entrance to a phreatic cave system that includes over 7.8 km of surveyed conduits. During the event, river stage increased over base flow conditions for approximately 25 days by a maximum of 8%. Intrusion of the river water was monitored with conductivity, temperature and depth sensors that were installed within the cave system and adjacent wells. Decreased specific conductivity within the cave system occurred for approximately 20 days, reflecting the length of time that river water was present in the cave system. During this time, grab samples were collected seven times over a period of 34 days for measurements of major ion and trace metal concentrations at the spring vent and at Martz sink, a karst window connected to the conduit system approximately 150 meters from the spring vent. Relative fractions of surface water and groundwater were estimated based on Cl concentrations of the samples, assuming conservative two end-member mixing during the event. This mixing model indicates that maximum river water contribution to the groundwater system was approximately 20%. River water had concentrations of iron, manganese, and other

  11. Blade-order-dependent radiocarbon variability in brown seaweed (Undaria pinnatifida) reflected a cold Oyashio water intrusion event in an embayment of the Sanriku coast, northeastern Japan

    Science.gov (United States)

    Satoh, N.; Fukuda, H.; Miyairi, Y.; Yokoyama, Y.; Nagata, T.

    2015-12-01

    Radiocarbon in dissolved inorganic carbon (DIC) in seawater varies greatly, both geographically and with depth. This "reservoir effect" is thought to be reflected in the radiocarbon content (∆14C) of marine organisms, via DIC fixation by primary producers and subsequent trophic transfer. The ∆14C of marine organismal soft tissues might thus provide unique information about their habitats, diets, migration and other environmental histories. However, the effectiveness of this approach has yet to be extensively explored, with data on ∆14C variability in soft tissues of marine organisms being markedly limited. Here we examined whether ∆14C values of individual pinnate blades (leaf-like structures) of brown seaweed (Undaria pinnatifida) reflect the ∆14C of DIC in the water current prevailing at the time of blade formation. The study was conducted in Otsuchi Bay located in the Sanriku coastal region, northeastern Japan, where 14C-depleted cold Oyashio current and warm Tsugaru current (high ∆14C) converge, affecting the physiology and growth of marine organisms growing there. U. pinnatifida individuals cultured in the bay (length of saprophytes, 140-215 cm) were harvested in April 2014 and ∆14C of blades were determined by accelerator mass spectrometry. Younger blades formed after the Oyashio water intrusion had significantly lower ∆14C values compared to older blades formed before the event. The ∆14C values of younger and older blades were generally consistent with the ∆14C of DIC in Oyashio (-60.5 ‰) and Tsugaru (24.9 ‰) waters, respectively. Thus, despite possible turnover of organic carbon in seaweed soft tissues, blade-order-dependent ∆14C variability appeared to strongly reflect the Oyashio intrusion event (radiocarbon shift) in the bay.

  12. Simulation of Variable-Density Ground-Water Flow and Saltwater Intrusion beneath Manhasset Neck, Nassau County, New York, 1905-2005

    Science.gov (United States)

    Monti, Jack; Misut, Paul E.; Busciolano, Ronald

    2009-01-01

    The coastal-aquifer system of Manhasset Neck, Nassau County, New York, has been stressed by pumping, which has led to saltwater intrusion and the abandonment of one public-supply well in 1944. Measurements of chloride concentrations and water levels in 2004 from the deep, confined aquifers indicate active saltwater intrusion in response to public-supply pumping. A numerical model capable of simulating three-dimensional variable-density ground-water flow and solute transport in heterogeneous, anisotropic aquifers was developed using the U.S. Geological Survey finite-element, variable-density, solute-transport simulator SUTRA, to investigate the extent of saltwater intrusion beneath Manhasset Neck. The model is composed of eight layers representing the hydrogeologic system beneath Manhasset Neck. Four modifications to the area?s previously described hydrogeologic framework were made in the model (1) the bedrock-surface altitude at well N12191 was corrected from a previously reported value, (2) part of the extent of the Raritan confining unit was shifted, (3) part of the extent of the North Shore confining unit was shifted, and (4) a clay layer in the upper glacial aquifer was added in the central and southern parts of the Manhasset Neck peninsula. Ground-water flow and the location of the freshwater-saltwater interface were simulated for three conditions (time periods) (1) a steady-state (predevelopment) simulation of no pumping prior to about 1905, (2) a 40-year transient simulation based on 1939 pumpage representing the 1905-1944 period of gradual saltwater intrusion, and (3) a 60-year transient simulation based on 1995 pumpage representing the 1945-2005 period of stabilized withdrawals. The 1939 pumpage rate (12.1 million gallons per day (Mgal/d)) applied to the 1905-1944 transient simulation caused modeled average water-level declines of 2 and 4 feet (ft) in the shallow and deep aquifer systems from predevelopment conditions, respectively, a net decrease of 5

  13. 基于 EFDC 的咸潮上溯对闽江下游水源地的影响%Influence of saltwater intrusion on water source land in downstream of Minjiang River based on EFDC

    Institute of Scientific and Technical Information of China (English)

    潘红澈; 逄勇; 罗缙; 张鹏; 谢蓉蓉

    2015-01-01

    In order to insure the water safety of water source affected by saltwater intrusion in the down-stream of Minjiang River ,the paper established a two -dimensional numerical model based on environ-mental fluid dynamics code (EFDC).It calibrated the parameters of the model by using synchronous data in December 2013 and simulated the distance of salinity intrusion and the impact on water source land un-der the condition of different flows .Results indicate that the range of salinity intrusion is negatively corre-lated with the discharged;the increase of saltwater intrusion distance will extend the unsuitable water in-take time of water source in the downstream of Minjiang River .In order to mitigate the impact of saltwater intrusion on water source , the paper recommended that it is necessary to optimize the operation ways of Shuikou reservoir and increase discharged .%为保障咸潮上溯情况下闽江下游水源地供水安全,建立基于EFDC的二维水环境数学模型,利用2013年12月同步监测资料进行参数率定,模拟不同流量条件下咸潮上溯的距离以及对水源地的影响。结果表明:咸潮上溯距离与下泄流量成负相关关系;咸潮上溯距离的增加将延长下游水源地的不宜取水时间。为减缓咸潮上溯对闽江下游水源地的影响,建议优化水口水库调度方式,加大下泄流量。

  14. Research Project on CO2 Geological Storage and Groundwater Resources: Water Quality Effects Caused by CO2 Intrusion into Shallow Groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Birkholzer, Jens; Apps, John; Zheng, Liange; Zhang, Yingqi; Xu, Tianfu; Tsang, Chin-Fu

    2008-10-01

    One promising approach to reduce greenhouse gas emissions is injecting CO{sub 2} into suitable geologic formations, typically depleted oil/gas reservoirs or saline formations at depth larger than 800 m. Proper site selection and management of CO{sub 2} storage projects will ensure that the risks to human health and the environment are low. However, a risk remains that CO{sub 2} could migrate from a deep storage formation, e.g. via local high-permeability pathways such as permeable faults or degraded wells, and arrive in shallow groundwater resources. The ingress of CO{sub 2} is by itself not typically a concern to the water quality of an underground source of drinking water (USDW), but it will change the geochemical conditions in the aquifer and will cause secondary effects mainly induced by changes in pH, in particular the mobilization of hazardous inorganic constituents present in the aquifer minerals. Identification and assessment of these potential effects is necessary to analyze risks associated with geologic sequestration of CO{sub 2}. This report describes a systematic evaluation of the possible water quality changes in response to CO{sub 2} intrusion into aquifers currently used as sources of potable water in the United States. Our goal was to develop a general understanding of the potential vulnerability of United States potable groundwater resources in the event of CO{sub 2} leakage. This goal was achieved in two main tasks, the first to develop a comprehensive geochemical model representing typical conditions in many freshwater aquifers (Section 3), the second to conduct a systematic reactive-transport modeling study to quantify the effect of CO{sub 2} intrusion into shallow aquifers (Section 4). Via reactive-transport modeling, the amount of hazardous constituents potentially mobilized by the ingress of CO{sub 2} was determined, the fate and migration of these constituents in the groundwater was predicted, and the likelihood that drinking water

  15. Interior intrusion detection systems

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.R.; Matter, J.C. (Sandia National Labs., Albuquerque, NM (United States)); Dry, B. (BE, Inc., Barnwell, SC (United States))

    1991-10-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs.

  16. Interior intrusion detection systems

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, J.R.; Matter, J.C. (Sandia National Labs., Albuquerque, NM (United States)); Dry, B. (BE, Inc., Barnwell, SC (United States))

    1991-10-01

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing interior intrusion detection systems. Interior intrusion sensors are discussed according to their primary application: boundary-penetration detection, volumetric detection, and point protection. Information necessary for implementation of an effective interior intrusion detection system is presented, including principles of operation, performance characteristics and guidelines for design, procurement, installation, testing, and maintenance. A glossary of sensor data terms is included. 36 figs., 6 tabs.

  17. The role of estrogen in intrusive memories.

    Science.gov (United States)

    Cheung, Jessica; Chervonsky, Liza; Felmingham, Kim L; Bryant, Richard A

    2013-11-01

    Intrusive memories are highly vivid, emotional and involuntary recollections which cause significant distress across psychological disorders including posttraumatic disorder (PTSD). Recent evidence has potentially extended our understanding of the development of intrusive memories by identifying biological factors which significantly impact on memories for emotionally arousing stimuli. This study investigated the role of stress on the development of intrusions for negative and neutral images, and indexed the potential contributions of sex (estrogen and progesterone) and stress (noradrenaline and cortisol) hormones. Whilst viewing the images, half the participants underwent a cold pressor stress (CPS) procedure to induce stress while the control participants immersed their hands in warm water. Saliva samples were collected to index estrogen, progesterone and noradrenergic and cortisol response. Participants (55 university students, 26 men, 29 women) viewed a series of negatively arousing and neutral images. Participants completed recall and intrusions measures 2 days later. Negative images resulted in greater recall and more intrusions than neutral images. In the cold water condition females recalled fewer neutral memories than males. Cortisol increase predicted decreased recall of negative memories in males, and estrogen predicted increased intrusions of negative images in women. These findings are consistent with evidence that circulating levels of ovarian hormones influence memory for emotionally arousing events, and provides the first evidence of the influence of sex hormones on intrusive memories. These results provide one possible explanation for the higher incidence of anxiety disorders in women.

  18. The use of airborne electromagnetic for efficient mapping of salt water intrusion and outflow to the sea

    DEFF Research Database (Denmark)

    Auken, Esben; Kirkegaard, Casper; Ribeiro, Joana;

    2010-01-01

    Airborne electromagnetic (AEM) is an efficient tool for mapping groundwater resources in sedimentary environments. AEM delivers a very high data coverage and results in high-resolution electrical images of the subsurface. In particular the time domain methods (TEM) are well suited for mapping o0f...... not only the salt-fresh water boundary in the coastal zone, but also the mixing of fresh-salt-water on the seaside. Even freshwater layers under several meters of brackish water can be mapped. Sufficient depth of investigation is obtained by time domain methods as they have a significant higher transmitter...

  19. Sudden intrusion of corrosive bottom water into the South Atlantic during the Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Meissner, K. J.; Alexander, K.; Bralower, T. J.

    2015-12-01

    The Paleocene-Eocene Thermal Maximum, ˜55 million years before present, was a period of rapid warming marked by a negative carbon isotope excursion and widespread dissolution of seafloor carbonate. These changes have been attributed to a massive release of carbon into the exogenic carbon cycle, and thus, the event provides an analog for future climate and environmental changes given the current anthropogenic CO2 emissions. Previous attempts to constrain the amount of carbon released have produced widely diverging results, between 2000 and 10,000 gigatons carbon (GtC). Sediment records indicate that acidification of deep waters was generally more extensive and severe in the Atlantic and Caribbean regions, with more modest changes in the Southern and Pacific Oceans. Here we compare simulations integrated with the UVic Earth System Climate Model with reconstructions of temperature and dissolution to present a mechanism that might explain the observed spatial differences and to constrain the total mass of carbon released. Due to the late Paleocene topography, highly corrosive waters accumulate in the deep North Atlantic before the PETM in our simulations. Several thousand years into the event, deep ocean warming destabilizes the North Atlantic water column and triggers deep water formation. This causes the corrosive bottom water to spill over an equatorial sill into the South Atlantic and through the Southern and Pacific Oceans, progressively gaining alkalinity. The simulated pattern of sediment dissolution along the path taken by this corrosive water is consistent with most dissolution estimates made from CaCO3 measurements in the Paleocene-Eocene sediment record. We find two scenarios that agree best with proxy data: a carbon release of 7000 GtC in combination with pre-event atmospheric carbon dioxide concentrations of 840 ppm and a carbon release of 7000-10,000 GtC with pre-event CO2 concentrations of 1680 ppm.

  20. Salt intrusion study in Cochin estuary - Using empirical models

    Digital Repository Service at National Institute of Oceanography (India)

    Jacob, B.; Revichandran, C.; NaveenKumar, K.R.

    Intensive measurements of salt intrusion are taken at high and low waters during spring and neap tide for each month respectively from June 2007 to May 2008. Salt intrusion length at high water varied from 10 km in monsoon 2008 to more than 40 km...

  1. SEAWATER INTRUSION TYPES AND REGIONAL DIVISIONS IN THE SOUTHERN COAST OF LAIZHOU BAY

    Institute of Scientific and Technical Information of China (English)

    孟广兰; 韩有松; 王少青; 王珍岩

    2002-01-01

    The southern coast of Laizhou Bay, Bohai Sea, is one of the areas in China most seriously impacted by seawater intrusion. Based on the sources of intruding waterbedies, seawater intrusion can be divided into two types: intrusion of saline water derived from modern seawater, and intrusion of subsurface brine and saline water derived from paleo-seawater in shallow Quaternary sediments. There are some distinct differences in their formation, mechanism and damage. The subsurface brine intrusion is a special type, which can cause very serious disaster. The coastal landform and the Quaternary hydrogeological environment are predominant factors in the classification of seawater intrusion types. Various coastal environments in different coastal sections result in three types of intrusion: seawater intrusion, saline groundwater intrusion, and mixed seawater and saline water intrusion, in the southern coast of Laizhou Bay, which can be divided into four areas: the sea-water intrusion area in the northern Laizhou City coast, the mixed seawater and saline groundwater intrusion area in the Baisha River-Jiaolai River mouth plain area, the mixed seawater and saline groundwater intrusion area in the Weihe River mouth plain area northern Changyi county coast, and the saline ground-water intrusion area in the northern Shouguang plains.

  2. The Use of PB-210 in Deciphering the Rate of Salt-Water Intrusion in South Florida.

    Science.gov (United States)

    Holmes, C. W.

    2001-12-01

    Over past few decades, short-lived isotopes (Pb-210 and Cs-137) have been used to decipher many sedimentary problems. The distribution of these isotopes have been modeled to give ages, sediment accumulation rates and define sedimentary depocenters. In south Florida, these isotopes have been used extensively in the paleoecologic studies. One serendipitous discovery was that these isotopes are also useful in defining the paleohydrography. It was discovered, that in addition to the normal surface distribution, abnormally high concentrations of Pb-210 and Cs-137 were present at the sediment rock interface. Examination of the regional distribution reveled that in the sediments overlying freshwater, disequilibrium existed between Pb-210 and its grandparent Ra-226. In the regions underlain by marine groundwater, Pb-210 was found to be in equilibrium. In the transition zone between the marine and freshwater intermediate disequilibria and detectable Cs-137 were found. The Pb-210 disequilibrium is a result of the thermodynamic differences between the fresh and the marine groundwater. The cooler freshwater has a higher capacity to absorb gases than the warmer marine groundwater. Thus radon, a decay product of uranium present in the carbonate substrate of south Florida, builds up in the freshwater but is rapidly dispersed from warm marine groundwater environments. The radon, enriched the fresh groundwater, defuses into the overlying peat, a natural radon absorbent, and rapidly decays to Pb-210. In the fresh to marine transition zone, the differences in thermodynamic properties between the two water masses create a condition similar to an open soda bottle. The result is upwelling of water enriched in radon and other dissolved ions. Cs-137, which has entered the groundwater in the recharge regions, is transported in this upwelling and like radon is adsorbed on the peat. As the marine water encroaches, the transition zone also migrates. The conditions producing the Pb-210

  3. Computer Intrusions and Attacks.

    Science.gov (United States)

    Falk, Howard

    1999-01-01

    Examines some frequently encountered unsolicited computer intrusions, including computer viruses, worms, Java applications, trojan horses or vandals, e-mail spamming, hoaxes, and cookies. Also discusses virus-protection software, both for networks and for individual users. (LRW)

  4. Mobilization of arsenic, lead, and mercury under conditions of sea water intrusion and road deicing salt application

    Science.gov (United States)

    Sun, Hongbing; Alexander, John; Gove, Brita; Koch, Manfred

    2015-09-01

    Water geochemistry data from complexly designed salt-solution injection experiments in the laboratory, coastal aquifers of Bangladesh and Italy, taken from the literature, and two salted watersheds of New Jersey, US were collected and analyzed to study the geochemical mechanisms that mobilize As, Pb, and Hg under varied salting conditions. Overall, increased NaCl-concentrations in aquifers and soil are found to increase the release of Pb and Hg into the water. Reducing environments and possible soil dispersion by hydrated Na+ are found to lead to an increase of As-concentration in water. However, the application of a pure NaCl salt solution in the column injection experiment was found to release less As, Pb, and Hg initially from the soil and delay their concentration increase, when compared to the application of CaCl2 and NaCl mixed salts (at 6:4 weight ratio). The concentration correlation dendrogram statistical analyses of the experimental and field data suggest that the release of As, Hg, and Pb into groundwater and the soil solution depends not only on the salt level and content, but also on the redox condition, dissolved organic matter contents, competitiveness of other ions for exchange sites, and source minerals. With the ongoing over-exploration of coastal aquifers from increased pumping, continued sea-level rise, and increased winter deicing salt applications in salted watersheds of many inland regions, the results of this study will help understand the complex relation between the concentrations of As, Pb, and Hg and increased salt level in a coastal aquifer and in soils of a salted watershed.

  5. Zircon Recycling in Arc Intrusions

    Science.gov (United States)

    Miller, J.; Barth, A.; Matzel, J.; Wooden, J.; Burgess, S.

    2008-12-01

    Recycling of zircon has been well established in arc intrusions and arc volcanoes, but a better understanding of where and how zircons are recycled can help illuminate how arc magma systems are constructed. To that end, we are conducting age, trace element (including Ti-in-zircon temperatures; TzrnTi) and isotopic studies of zircons from the Late Cretaceous (95-85 Ma) Tuolumne Intrusive Suite (TIS) in the Sierra Nevada Batholith (CA). Within the TIS zircons inherited from ancient basement sources and/or distinctly older host rocks are uncommon, but recycled zircon antecrysts from earlier periods of TIS-related magmatism are common and conspicuous in the inner and two most voluminous units of the TIS, the Half Dome and Cathedral Peak Granodiorites. All TIS units have low bulk Zr ([Zr]825°C), [Zr] in the TIS is a factor of 2 to 3 lower than saturation values. Low [Zr] in TIS rocks might be attributed to a very limited supply of zircon in the source, by disequilibrium melting and rapid melt extraction [1], by melting reactions involving formation of other phases that can incorporate appreciable Zr [2], or by removal of zircon at an earlier stage of magma evolution. Based on a preliminary compilation of literature data, low [Zr] is common to Late Cretaceous N.A. Cordilleran granodioritic/tonalitic intrusions (typically Tzrnsat [3]. A corollary is that slightly older zircon antecrysts that are common in the inner units of the TIS could be considered inherited if they are derived from remelting of slightly older intrusions. Remelting at such low temperatures in the arc would require a source of external water. Refs: [1] Sawyer, J.Pet 32:701-738; [2] Fraser et al, Geology 25:607-610; [3] Harrison et al, Geology 35:635- 638

  6. Types of saltwater intrusion of the Changjiang Estuary

    Institute of Scientific and Technical Information of China (English)

    茅志昌; 沈焕庭; JamesT.Liu; D.Eisma

    2001-01-01

    The Changjiang Estuary is characterized by multi-order bifurcations, unsteady submerged sandbars, mid-channel sandbars, creeks and riffles. The following four types of saltwater intrusion are found: (1) direct intrusion from the sea; (2) intrusion during tidal flooding; (3) intrusion from tidal flats overflow; and (4) salt water coming upstream through other waterways. These result in a complicated temporal and spatial salinity distribution. A high chlorinity concentration zone exists from the Liuhekou to the Sidongkou along the South Branch. The salinity during neap tide or ordinary tide is higher than during spring tide.

  7. Network intrusion detection

    Institute of Scientific and Technical Information of China (English)

    Oboile Tirelo; YANG Chun-hua

    2003-01-01

    Nowadays, network computer systems play an increasingly important role in society and economy. They have become the targets of a wide array of malicious attacks that invariably turn into actual intrusions. This is why the computer security has become an essential concern for network administrators. Too often, intrusions wreak havoc inside LANs and the time and cost to repair the damage can grow to extreme proportions. Instead of using passive measures to fix and patch security holes once they have been exploited, it is more effective to adopt a protective approach to intrusions. In addition to the well-established intrusion prevention techniques such as data encryption and message integrity, user authentication and user authorization, as well as the avoidance of security flaws inherent to many off-the-shelf applications, intrusion detection techniques can be viewed as an addition safeguard for network computers. The paper discusses traditional and new security designs, the approach to implementing best-practice security measures and the method to trace the malicious computer attackers.

  8. Network Intrusion Dataset Assessment

    Science.gov (United States)

    2013-03-01

    Science, pages 576–585. Springer Berlin / Heidelberg, June 2010. • Jing Xiao-Pei and Wang Hou -Xiang. “A new immunity intrusion detection model based on...2008. • Hongying Zheng, Meiju Hou , and Yu Wang. “An efficient hybrid clustering-PSO algorithm for anomaly intrusion detection.” Journal of Software...Technology, 2(6):1790– 1799, 2010. [34] Lee, Suchul, Hyunchul Kim, Dhiman Barman, Sungryoul Lee, Chong -kwon Kim, Ted Kwon, and Yanghee Choi. “NeTraMark: a

  9. Oil-material fractionation in Gulf deep water horizontal intrusion layer: Field data analysis with chemodynamic fate model for Macondo 252 oil spill.

    Science.gov (United States)

    Melvin, A T; Thibodeaux, L J; Parsons, A R; Overton, E; Valsaraj, K T; Nandakumar, K

    2016-04-15

    Among the discoveries of the Deepwater Horizon blowout was the so-called "sub-surface plume"; herein termed the "oil-trapping layer". Hydrocarbons were found positioned at ~1100-1300m with thickness ~100-150m and moving horizontally to the SW in a vertically stratified layer at the junction of the cold abyssal water and the permanent thermocline. This study focuses on its formation process and fate of the hydrocarbons within. The originality of this work to the field is two-fold, first it provides a conceptual framework which places layer origin in the context of a horizontal "intrusion" from the near-field, vertical, blow-out plume and second, it offers a theoretical model for the hydrocarbon chemicals within the horizontal layer as it moves far-afield. The model quantifies the oil-material fractionation process for the soluble and fine particle. The classical Box model, retrofitted with an internal gradient, the "G-Box", allows an approach that includes turbulent eddy diffusion coupled with droplet rise velocity and reactive decay to produce a simple, explicit, transparent, algebraic model with few parameters for the fate of the individual fractions. Computations show the soluble and smallest liquid droplets moving very slowly vertically through the layer appearing within the trapping layer at low concentration with high persistence. The larger droplets move-through this trapping zone quickly, attain high concentrations, and eventually form the sea surface slick. It impacts the field of oil spill engineering science by providing the conceptual idea and the algorithms for projecting the quantities and fractions of oil-material in a deep water, horizontal marine current being dispersed and moving far afield. In the field of oil spill modeling this work extends the current generation near-field plume source models to the far-field. The theory portrays the layer as an efficient oil-material trap. The model-forecasted concentration profiles for alkanes and aromatics

  10. SEAWATER INTRUSION TYPES AND REGIONAL DIVISIONS IN THE SOUTHERN COAST OF LAIZHOU BAY

    Institute of Scientific and Technical Information of China (English)

    孟广兰; 韩有松; 王少青; 王珍岩

    2002-01-01

    The southern coast of Laizhou Bay, Bohai Sea, is one of the areas in China most seriously impacted by seawater intrusion. Based on the sources of intruding wate rbodies, seawater intrusion can be divided into two types: intrusion of saline water derived from modern seawater, and intrusion of subsurface brine and saline water derived from paleo-seawater in shallow Quaternary sediments. There are so me distinct differences in their formation, mechanism and damage. The subsurface brine intrusion is a special typ e, which can cause very serious disaster.The coastal landform and the Quaternary hydrogeological environment are pr edominant factors in the classification of seawater intrusion types. Various coastal environments in diff erent coastal sections result in three types of intrusion: seawater intrusion, saline groundwater intrusion, and mixed seawater and saline water intrusion, in the southern coast of Laizhou Bay, which can be divided into four areas: the seawater intrusion area in the northern Laizhou City coast, the mixed seawater and saline groundwater in trusion area in the Baisha River-Jiaolai River mouth plain area, the mixed seawater and saline groundwater intrus ion area in the Weihe River mouth plain area northern Changyi county coast, and the saline groundwater intrusion area in the northern Shouguang plains.

  11. Spatial and temporal variability of the North Korean Cold Water leading to the near-bottom cold water intrusion in Korea Strait [review article

    Science.gov (United States)

    Yun, Jae-Yul; Magaard, Lorenz; Kim, Kuh; Shin, Chang-Woong; Kim, Cheolsoo; Byun, Sang-Kyung

    2004-01-01

    In the deepest region of Korea Strait, the surface temperature is highest in August (lowest in March), while the near-bottom temperature is lowest in September (highest in May). Cross-spectral analysis of the monthly temperature data between the two layers shows high coherence at the annual frequency with phase of 154°. Why and how does such a nearly opposite phasing occur between the surface and the near-bottom temperatures there? This study aims at answering these questions using historical and recently observed data. Cold and relatively fresh subsurface water flowing southward along the east coast of Korea and, known as the North Korean Cold Water (NKCW), becomes noticeable in April near the Sokcho coast. The zonal temperature gradient there is largest around June. The width of the NKCW becomes larger from April to August. After October, the NKCW retreats back toward the coast. The southward movement of the NKCW is thus strong over a period of six to seven months and weak in winter, especially in February. The NKCW flows southward relatively quickly along the coast in April to October and arrives at the Ulleung Basin within one to two months. Because of the sill between the Ulleung Basin and Korea Strait, this water cannot continue to flow to south, but piles up for about two to three months before it moves over the sill. The convergence of the subsurface cold water in the Ulleung Basin displaces the isopycnals upward and this water then intrudes over the sill along the isopycnals. This explains why in April or May, when this water appears noticeably at the Sokcho coast, the near-bottom water in Korea Strait is warmest and in August or September when the NKCW, which is piled up enough at the southern end of the Ulleung Basin, intrudes to Korea Strait, the near-bottom temperatures there are at their lowest. The origin of the NKCW seems to be the water of salinity less han 34.1 psu and surface density of 27 σθ or higher, which sinks in the northwestern East Sea

  12. Oceanic dispersion of radioactive cesium in the western North Pacific - Eastward dispersion in surface water and southward intrusion with mode water

    Energy Technology Data Exchange (ETDEWEB)

    Kaeriyama, Hideki; Ambe, Daisuke; Shigenobu, Yuya; Fujimoto, Ken; Ono, Tsuneo; Watanabe, Tomowo [National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4, Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648 (Japan); Morita, Takami [Fisheries Research Agency, 2-3-3, Minato Mirai, Nishi-ku, Yokohama, Kanagawa 220-6115 (Japan)

    2014-07-01

    The Fukushima Dai-ichi Nuclear Power Plant (FNPP) accident after the Great East Japan Earthquake and tsunami on 11 March 2011 resulted in elevation of the level of anthropogenic radioactivity in the marine environment in the western North Pacific from atmospheric fallout and direct discharges of highly radioactive liquid waters. Intensive monitoring on iodine-131, cesium-134 (Cs-134) and cesium-137 (Cs-137) in seawater near offshore FNPP, and those in marine organisms in the broad area around Japan were conducted, while the information of radioactive contamination in the North Pacific is still limited due to the limitation of the observational data. In this study, we report the concentrations of Cs-134 and Cs-137 in seawater collected from western North Pacific during June 2011 and November 2012. The eastward dispersion of FNPP-derived radioactive cesium in the surface water has been observed with prevention of southward dispersion due to the strong eastward current (Kuroshio Extension; KE) in the North Pacific. Although the concentrations of Cs-134 and Cs-137 were remarkably decreased between 2011 and 2012 at 145 deg. E and 155 deg. E, they were almost comparable between these two years at 175 deg. E. The inventories of Cs-137 between 0-500 m around KE at 147 deg. E were ranged from 3800 to 11000 Bq/m{sup 2} in October 2011, and from 1000 to 2400 Bq/m{sup 2} in November 2012. Surface water had the highest concentration of radioactive Cs at northern part of KE, subsurface peak of radioactive Cs were observed at KE and south of KE in both years. Furthermore, the southward dispersion of FNPP-derived radioactive Cs in the subsurface waters were also observed south of Japan Islands. We found the FNPP-derived Cs-134 (1.8-6.8 mBq/kg) at southernmost 18 deg. N, 135 deg. deg. E in September 2012. The potential density at the subsurface peaks of Cs-134 and increase of water column inventories of Cs-137 after the winter season of 2011-2012, suggested that the main water mass

  13. Heavy metal contamination in bore water due to industrial pollution and polluted and non polluted sea water intrusion in Thoothukudi and Tirunelveli of South Tamil Nadu, India.

    Science.gov (United States)

    Puthiyasekar, C; Neelakantan, M A; Poongothai, S

    2010-12-01

    This study investigates the pollution vulnerability of bore water in the coastal region of Tirunelveli and Thoothukudi in the state of Tamilnadu, India. There are no industries in the Tirunelveli Coastal area whereas there are many industries in SIPCOT (State Industries Promotion Corporation of Tamilnadu) Thoothukudi, and coastal area of Thoothukudi. Bore water from the SIPCOT, coastal area of Thoothukudi and Tirunelveli were collected periodically from July 2006 to May 2008 for this study. These samples were tested and analyzed to find the concentrations of sodium, magnesium, aluminium, potassium, calcium, copper, cadmium, mercury and lead. The toxic cadmium concentration was found in the range of 0.00-0.22 mg Kg⁻¹ at SIPCOT 2 in November 2007, mercury 0.00-0.024 mg Kg⁻¹ and lead 0.00-0.02 mg Kg⁻¹ in SIPCOT 2 in January 2008. The level of contamination is higher than the WHO limits of drinking water standards; but copper and aluminium content are within the limit. On the other hand, the samples taken from bores in Tirunelveli coastal area are non-polluted, and the analysis shows that all the metals are within the limits of WHO standard.

  14. Wireless Intrusion Prevention Systems

    Directory of Open Access Journals (Sweden)

    Jack TIMOFTE

    2008-01-01

    Full Text Available The wireless networks have changed the way organizations work and offered a new range of possibilities, but at the same time they introduced new security threats. While an attacker needs physical access to a wired network in order to launch an attack, a wireless network allows anyone within its range to passively monitor the traffic or even start an attack. One of the countermeasures can be the use of Wireless Intrusion Prevention Systems.

  15. Boron isotope method for study of seawater intrusion

    Institute of Scientific and Technical Information of China (English)

    肖应凯; 尹德忠; 刘卫国; 王庆忠; 魏海珍

    2001-01-01

    A distinct difference in boron isotopes between seawater and terrestrial water is emphasized by δ11B values reported for seawater and groundwater, with an average of 38.8‰ and in the range of -8.9‰ to 9.8‰, respectively. The isotopic composition of boron in groundwater can be used to quantify seawater intrusion and identify intrusion types, e.g. seawater or brine intrusions with different chemical and isotopic characteristics, by using the relation of δ11B and chloride concentration. The feasibility of utilizing boron isotope in groundwater for studying seawater intrusion in Laizhou Bay Region, China, is reported in this study, which shows that boron isotope is a useful and excellent tool for the study of seawater intrusion.

  16. Physical model simulations of seawater intrusion in unconfined aquifer

    Directory of Open Access Journals (Sweden)

    Tanapol Sriapai

    2012-12-01

    Full Text Available The objective of this study is to simulate the seawater intrusion into unconfined aquifer near shoreline and to assessthe effectiveness of its controlling methods by using scaled-down physical models. The intrusion controlled methods studiedhere include fresh water injection, saltwater extraction, and subsurface barrier. The results indicate that under natural dynamicequilibrium between the recharge of fresh water and the intrusion well agree with the Ghyben-Herzberg mathematical solution.Fresh water pumping from the aquifer notably move the fresh-salt water interface toward the pumping well, depending on thepumping rates and the head differences (h between the aquifer recharge and the salt water level. The fresh water injectionmethod is more favorable than the salt water extraction and subsurface barrier method. The fresh water injection rate of about10% of the usage rate can effectively push the interface toward the shoreline, and keeping the pumping well free of salinity.

  17. Sources for saltwater intrusion at the water intake of Qingcaosha Reservoir in the Changjiang Estuary%长江河口青草沙水库盐水入侵来源

    Institute of Scientific and Technical Information of China (English)

    陈泾; 朱建荣

    2014-01-01

    应用改进的三维数值模式 ECOM-si,从模式计算的盐度和流向的变化过程、涨憩和落憩时刻盐度等值线和淡水区域的变化,分析在一般动力条件下青草沙水库取水口盐水入侵来源。计算结果表明,小潮后中潮、大潮、大潮后中潮和小潮期间北支倒灌占青草沙水库取水口表层盐水入侵比例分别为69.5%、89.3%、98.5%和99.5%,占底层盐水入侵比例分别为34.9%、88.9%、98.5%和99.5%。除了小潮后中潮期间底层盐水入侵来源主要来自下游外海(占65.1%),青草沙水库取水口表层和底层盐水入侵来源主要来自北支盐水倒灌,尤其是大潮后中潮和小潮期间几乎全部来自北支盐水倒灌。%Based on temporal variation of the simulated salinity and current direction,change of the isohaline and freshwater zone at flood slack and ebb slack,this study used the modified numerical 3-D model ECOM-si to analyze sources of saltwater intrusion at the water intake of Qingcaosha Reservoir under normal dynamic condition.The modeled results showed that saltwater-spill-over from the North Branch into the South Branch(SSO)accounts for 69.5%,89.3%,98.5% and 99.5% of the surface saltwater intrusion at the water intake of the Qingcaosha Reser-voir during moderate tide following neap tide,spring tide,moderate tide following spring tide and neap tide,respec-tively,and 34.9%,88.9%,98.5%,99.5% of the bottom saltwater intrusion at the water intake of the reservoir during the same four-type tides mentioned above.Except for the bottom saltwater intrusion mainly from down-stream open sea (accounts for 65.1%)during moderate tide following neap tide,the source of the saltwater intru-sion at surface and bottom layer at the water intake of the reservoir is mainly from the SSO,especially during mod-erate tide following spring and neap tide.

  18. 千岛湖配水工程对钱塘江河口盐水入侵影响%Effects of Qiandao Lake water diversion project on Qiantang River estuary saltwater intrusion

    Institute of Scientific and Technical Information of China (English)

    张舒羽; 周维; 史英标

    2016-01-01

    Qiandao Lake water diversion project will change the runoff process of the Fuchun reservoir and the salini-ty of Qiantang River estuary. A two-dimensional numerical salinity model which including tidal bore′s action is estab-lished. Based on tide and salinity testing, the distance of saltwater intrusion and the exceeding period of important wa-ter inlets caused by the project are calculated. Results showed that, it will be significantly effected in the low flow year by the current scheduling scheme, the distance of saltwater intrusion is increased 3 700 meters and time available for water inlets time along the river is shorten 0. 2~3. 6 days, but it is little effected in normal and high flow year. In or-der to reduce the influence of the salt water intrusion which happened due to the project in low flow year, a reservoir optimal operation is necessary.%杭州市第二水源千岛湖配水工程(简称配水工程)的实施将引起富春江水库下泄流量及过程改变,从而对钱塘江河口盐水入侵产生影响。建立考虑涌潮作用的二维盐度数值模型,在验证钱塘江河口潮位和盐度的基础上,预测配水工程实施对河口盐水入侵距离和重要取水口含氯度超标时间的影响。研究表明:配水工程实施后,上游富春江水库若按现状调度方案,对枯水年影响大,咸水上溯距离增加3.7 km,沿岸取水口的可取水时间缩短0.2~3.6 d,丰、平水年盐水入侵和引水前相当;通过水库的优化调度,可基本消除枯水年引水造成的盐水入侵影响。为减少配水工程实施的盐水入侵影响,采用水库的优化调度模式是必要的。

  19. How stratospheric are deep stratospheric intrusions?

    Science.gov (United States)

    Trickl, T.; Vogelmann, H.; Giehl, H.; Scheel, H.-E.; Sprenger, M.; Stohl, A.

    2014-09-01

    Preliminary attempts of quantifying the stratospheric ozone contribution in the observations at the Zugspitze summit (2962 m a.s.l.) next to Garmisch-Partenkirchen in the German Alps had yielded an approximate doubling of the stratospheric fraction of the Zugspitze ozone during the time period 1978 to 2004. These investigations had been based on data filtering by using low relative humidity (RH) and elevated 7Be as the criteria for selecting half-hour intervals of ozone data representative of stratospheric intrusion air. To quantify the residual stratospheric component in stratospherically influenced air masses, however, the mixing of tropospheric air into the stratospheric intrusion layers must be taken into account. In fact, the dewpoint mirror instrument at the Zugspitze summit station rarely registers RH values lower than 10% in stratospheric air intrusions. Since 2007 a programme of routine lidar sounding of ozone, water vapour and aerosol has been conducted in the Garmisch-Partenkirchen area. The lidar results demonstrate that the intrusion layers are drier by roughly one order of magnitude than indicated in the in situ measurements. Even in thin layers RH values clearly below 1% have frequently been observed. These thin, undiluted layers present an important challenge for atmospheric modelling. Although the ozone values never reach values typical of the lower-stratosphere it becomes, thus, obvious that, without strong wind shear or convective processes, mixing of stratospheric and tropospheric air must be very slow in most of the free troposphere. As a consequence, the analysis the Zugspitze data can be assumed to be more reliable than anticipated. Finally, the concentrations of Zugspitze carbon monoxide rarely drop inside intrusion layers and normally stay clearly above full stratospheric values. This indicates that most of the CO, and thus the intrusion air mass, originates in the shallow "mixing layer" around the thermal tropopause. The CO mixing ratio in

  20. How stratospheric are deep stratospheric intrusions?

    Directory of Open Access Journals (Sweden)

    T. Trickl

    2014-06-01

    Full Text Available Preliminary attempts of quantifying the stratospheric ozone contribution in the observations at the Zugspitze summit (2962 m a.s.l. next to Garmisch-Partenkirchen in the German Alps had yielded an approximate doubling of the stratospheric fraction of the Zugspitze ozone during the time period 1978 and 2004. These investigations had been based on data filtering by using low relative humidity and elevated 7Be as the criteria for selecting half-hour intervals of ozone data representative of stratospheric intrusion air. For quantifying the residual stratospheric component in stratospherically influenced air masses, however, the mixing of tropospheric air into the stratospheric intrusion layers must be taken into account. In fact, the dew-point-mirror instrument at the Zugspitze summit station rarely registers relative humidity (RH values lower than 10% in stratospheric air intrusions. Since 2007 a programme of routine lidar sounding of ozone, water vapour and aerosol has been conducted in the Garmisch-Partenkirchen area. The lidar results demonstrate that the intrusion layers are dryer by roughly one order of magnitude than indicated in the in-situ measurements. Even in thin layers frequently RH values clearly below 1% have been observed. These thin, undiluted layers present an important challenge for atmospheric modelling. Although the ozone values never reach values typical of the lower-stratosphere it becomes, thus, obvious that, without strong wind shear or convective processes, mixing of stratospheric and tropospheric air must be very slow in most of the free troposphere. As a consequence, the analysis the Zugspitze data can be assumed to be more reliable than anticipated. Finally, the concentrations of Zugspitze carbon monoxide rarely drop inside intrusion layers and normally stay clearly above full stratospheric values. This indicates that most of the CO and, thus, the intrusion air mass originate in the shallow "mixing layer" around the

  1. How stratospheric are deep stratospheric intrusions?

    Directory of Open Access Journals (Sweden)

    T. Trickl

    2014-09-01

    Full Text Available Preliminary attempts of quantifying the stratospheric ozone contribution in the observations at the Zugspitze summit (2962 m a.s.l. next to Garmisch-Partenkirchen in the German Alps had yielded an approximate doubling of the stratospheric fraction of the Zugspitze ozone during the time period 1978 to 2004. These investigations had been based on data filtering by using low relative humidity (RH and elevated 7Be as the criteria for selecting half-hour intervals of ozone data representative of stratospheric intrusion air. To quantify the residual stratospheric component in stratospherically influenced air masses, however, the mixing of tropospheric air into the stratospheric intrusion layers must be taken into account. In fact, the dewpoint mirror instrument at the Zugspitze summit station rarely registers RH values lower than 10% in stratospheric air intrusions. Since 2007 a programme of routine lidar sounding of ozone, water vapour and aerosol has been conducted in the Garmisch-Partenkirchen area. The lidar results demonstrate that the intrusion layers are drier by roughly one order of magnitude than indicated in the in situ measurements. Even in thin layers RH values clearly below 1% have frequently been observed. These thin, undiluted layers present an important challenge for atmospheric modelling. Although the ozone values never reach values typical of the lower-stratosphere it becomes, thus, obvious that, without strong wind shear or convective processes, mixing of stratospheric and tropospheric air must be very slow in most of the free troposphere. As a consequence, the analysis the Zugspitze data can be assumed to be more reliable than anticipated. Finally, the concentrations of Zugspitze carbon monoxide rarely drop inside intrusion layers and normally stay clearly above full stratospheric values. This indicates that most of the CO, and thus the intrusion air mass, originates in the shallow "mixing layer" around the thermal tropopause. The

  2. Managing Temporal and Spatial Variability in Vapor Intrusion Data

    Science.gov (United States)

    2012-03-28

    Managing Temporal and Spatial Variability in Vapor Intrusion Data Todd McAlary, M.Sc., P.Eng., P.G. Geosyntec Consultants, Inc...TITLE AND SUBTITLE Managing Temporal and Spatial Variability in Vapor Intrusion Data 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...Koc (mL/g) OSWER indoor conc. at 10-6 risk (ppb) Vapour pressure (atm) Water solubility (g/l) 1,1,1-Trichloroethane 110 400

  3. Intrusive growth of sclerenchyma fibers

    NARCIS (Netherlands)

    Snegireva, A.V.; Ageeva, M.V.; Amenitskii, S.I.; Chernova, T.E.; Ebskamp, M.; Gorshkova, T.A.

    2010-01-01

    Intrusive growth is a type of cell elongation when the rate of its longitudinal growth is higher than that of surrounding cells; therefore, these cells intrude between the neighboring cells penetrating the middle lamella. The review considers the classical example of intrusive growth, e.g., elongati

  4. Solvents and vapor intrusion pathways.

    Science.gov (United States)

    Phillips, Scott D; Krieger, Gary R; Palmer, Robert B; Waksman, Javier C

    2004-08-01

    Vapor intrusion must be recognized appropriately as a separate pathway of contamination. Although many issues resemble those of other forms of contamination (particularly its entryway, which is similar to that of radon seepage), vapor intrusion stands apart as a unique risk requiring case-specific action. This article addresses these issues and the current understanding of the most appropriate and successful remedial actions.

  5. Evaluation of the Katz-Thompson model for estimating the water permeability of cement-based materials from mercury intrusion porosimetry data

    Energy Technology Data Exchange (ETDEWEB)

    El-Dieb, A.S.; Hooton, R.D. (Univ. of Toronto, Ontario (Canada). Dept. of Civil Engineering)

    1994-01-01

    The permeability of concrete is becoming a focal characteristic with regard to the durability and performance of cement-based materials, pastes, mortars and concretes. Since it is mainly affected by the microstructure of the porous media, many models and theories have been developed relating the permeability of porous media to their microstructural parameters. One which proved to be useful in predicting the permeability of sedimentary rock, from mercury intrusion porosimetry data, is the Katz-Thompson theory. A review of this theory and its assumptions is presented, and its applicability to cementitious materials is investigated using two sets of data of various hardened cement pastes and concretes. Also, the major differences between cement-based materials and sedimentary rock from the microstructural point of view is reported.

  6. 不同潮型和风况下青草沙水库取水口盐水入侵来源%Saltwater intrusion sources at the water intake of Qingcaosha reservoir in different tidal pattern and wind case

    Institute of Scientific and Technical Information of China (English)

    王绍祥; 朱建荣

    2015-01-01

    The measured salinity and numerical simulated current speed and direction in Decem-ber 2013 and February 2014 were used to analyze the source of saltwater intrusion at the water intake of Qingcaosha reservoir.Under the general river discharge and wind case in dry season December 2013,the saltwater sources at the water intake during spring tide,medium tide after spring tide,early neap tide came from the upstream saltwater-spill-over from the North Branch into the South Branch,whereas during late neap tide and medium tide after neap tide came from the downstream open sea,i.e.,through the saltwater intrusion in the North Channel.It was found that the saltwater intrusion in the Changjiang Estuary in February 2014 was very severe and had never been happened in recent decades,which resulted in the not suitable take water days of the reservoir reach to 23 days,and serious threat of safety water supply in Shanghai. Under the general river discharge and long continue strong northerlies lasting 15 days in Februar-y 2014,the saltwater sources at the water intake of Qingcaosha reservoir during the all four tidal patterns came from the downstream open sea saltwater intrusion through the North Channel.%本文应用2013年12月和2014 年 2月青草沙水库取水口实测盐度和数值模式计算的流速流向,分析水库取水口盐水入侵的来源.2013年12月枯季在一般径流量和风况的情况下,大潮、大潮后中潮和小潮前期水库取水口盐水来源于上游的北支倒灌,小潮中后期、小潮后中潮盐水入侵来源于北港下游外海的盐水入侵.观测资料发现2014 年 2月长江河口盐水入侵是近几十年来发生过的最严重盐水入侵事件,导致青草沙不宜取水的时间达到23 d,对上海的安全供水造成了严重威胁.2014 年 2月枯季在一般径流量和持续偏北大风15 d 情况下,所有4个潮型中青草沙水库取水口盐水均来自北港外海的正面入侵.

  7. Tropical upper tropospheric humidity variations due to potential vorticity intrusions

    Science.gov (United States)

    Sandhya, M.; Sridharan, S.; Indira Devi, M.

    2015-09-01

    Four cases (March 2009, May 2009, April 2010 and February 2012) are presented in which the ERA-interim relative humidity (RH) shows consistent increase by more than 50 % in the upper troposphere (200-250 hPa) over tropics at the eastward side of the potential vorticity (PV) intrusion region. The increase in RH is confirmed with the spaceborne microwave limb sounder observations and radiosonde observations over Gadanki (13.5° N, 79.2° E) and is observed irrespective of whether the PV intrusions are accompanied by deep convection or not. It is demonstrated that the increase in RH is due to poleward advection induced by the PV intrusions in their eastward side at the upper tropospheric heights. It is suggested that the low-latitude convection, which is not necessarily triggered by the PV intrusion, might have transported water vapour to the upper tropospheric heights.

  8. Saltwater intrusion in coastal regions of North America

    Science.gov (United States)

    Barlow, Paul M.; Reichard, Eric G.

    2010-01-01

    Saltwater has intruded into many of the coastal aquifers of the United States, Mexico, and Canada, but the extent of saltwater intrusion varies widely among localities and hydrogeologic settings. In many instances, the area contaminated by saltwater is limited to small parts of an aquifer and to specific wells and has had little or no effect on overall groundwater supplies; in other instances, saltwater contamination is of regional extent and has resulted in the closure of many groundwater supply wells. The variability of hydrogeologic settings, three-dimensional distribution of saline water, and history of groundwater withdrawals and freshwater drainage has resulted in a variety of modes of saltwater intrusion into coastal aquifers. These include lateral intrusion from the ocean; upward intrusion from deeper, more saline zones of a groundwater system; and downward intrusion from coastal waters. Saltwater contamination also has occurred along open boreholes and within abandoned, improperly constructed, or corroded wells that provide pathways for vertical migration across interconnected aquifers. Communities within the coastal regions of North America are taking actions to manage and prevent saltwater intrusion to ensure a sustainable source of groundwater for the future. These actions can be grouped broadly into scientific monitoring and assessment, engineering techniques, and regulatory approaches.

  9. 莱州湾南岸潍坊北部平原区咸水入侵动态变化分析%Analysis on Dynamic Changes of Salt Water Intrusion in Northern Weibei Plain in South Laizhou Bay

    Institute of Scientific and Technical Information of China (English)

    管清花; 陈学群; 张婧

    2014-01-01

    In this paper,setting northern Weifang plain in southern Laizhou Bay as the typical research area,geo-logical background of salt water formation and distribution have been described.Through water chemistry method, characteristics of water chemistry change of underground brine and the change of saltwater instrusion caused by hu-man activities in northern Weifang plain have been analyzed.Main causes of salt water intrusion has been analyzed as well.%以莱州湾南岸潍坊北部平原地区为典型研究区,阐述了咸水体形成的成因背景与分布特征。通过水化学分析的方法,分析了潍北平原地下水水化学变化特征,及人工开采导致咸水入侵的变化,并分析了咸水入侵的主要成因。

  10. Granitoid intrusions and related deposits

    Institute of Scientific and Technical Information of China (English)

    孟良义; 李绪俊

    1996-01-01

    Taking the Bainaimiao copper and gold deposits, Inner Mongolia and the Wushan copper deposits, Jiangxi Province as examples, a discussion is devoted to the relationship between the granitoid intrusions and related deposits from different lines of evidence: the spatial distribution, country rocks and alteration of the deposits, trace element contents and vertical zoning of elements in deposits, the metallogenic preference of granitoid intrusions, the metallogenic models and stable isotopic geology. It is concluded that the ore-bearing fluids mainly come from granitoid magmas and granitoid intrusions are closely associated with the related deposits in space.

  11. Novel Model for Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    Li Jia-chun; Li Zhi-tang

    2003-01-01

    It's very difficult that the traditional intrusion detection methods based on accurate match adapt to the blur and uncertainty of user information and expert knowledge, it results in failing to report the variations of attack signature. In addition security itself includes fuzziness, the judgment standard of confidentiality, integrity and availability of system resource is uncertain. In this paper fuzzy intrusion detection based on partial match is presented to detect some types of attacks availably and alleviate some of the difficulties of above approaches, the architecture of fuzzy intrusion detection system(FIDS) is introduced and its performance is analyzed.

  12. Novel Model for Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    Li; Jia-chun; Li; Zhi-tang

    2003-01-01

    It's very difficult that the traditional intrusion detection methods based on accurate match adapt to the blur and uncertainty of user information and expert knowledge, it results in failing to report the variation of attack signature.In addition security itself includes fuzziness, the judgment standard of confidentiality, integrity and availability of system resource is uncertain. In this paper fuzzy intrusion detection based on partial match is presented to detect some types of attacks availably and alleviate some of the difficulties of above approaches, the architecture of fuzzy intrusion detection system(FIDS) is introduced and its performance is analyzed.

  13. Recent advances in vapor intrusion site investigations.

    Science.gov (United States)

    McHugh, Thomas; Loll, Per; Eklund, Bart

    2017-02-22

    Our understanding of vapor intrusion has evolved rapidly since the discovery of the first high profile vapor intrusion sites in the late 1990s and early 2000s. Research efforts and field investigations have improved our understanding of vapor intrusion processes including the role of preferential pathways and natural barriers to vapor intrusion. This review paper addresses recent developments in the regulatory framework and conceptual model for vapor intrusion. In addition, a number of innovative investigation methods are discussed.

  14. 莱州湾南岸海(咸)水入侵监测技术方法体系构建%Construction of Sea(Salt)Water Intrusion Monitoring Techniques and Methods System in South Bank of Laizhou Bay

    Institute of Scientific and Technical Information of China (English)

    杜东; 刘宏伟; 刘志涛; 马云青; 朱雪芹

    2015-01-01

    海咸水入侵已是一个全球性的普遍问题,大量文献表明,人类活动已经涉及的沿海地段都已不同程度的发生海咸水入侵。在莱州湾南岸以发生咸水入侵为主,通过研究表明,该地区咸水入侵界面已逐渐向南迁移,严重影响该地区地下水资源的正常使用。监测咸水入侵对合理使用该地区的地下水资源意义重大,该文将构建莱州湾南岸咸水入侵监测技术方法体系。%Sea(salt)water intrusion is a global problem.As showed by a lot of datas,different levels sea salt water intrusion have happened in human living areas.Salt water intrusionhas happened in south bank of Laizhou bay.It is showed that the saltwater intrusion interface has been gradually migrated southward.It will seriously influence normal use of the groundwater resource.Monitoring of saltwater intrusion has great significance in reasonable use of groundwater resources in this area.In this paper,monitoring method system of salt water intrusion in south bank of Laizhou Bay has been set up.

  15. PENURUNAN TINGKAT INTRUSI AIR LAUT BERDASARKAN "CHLORIDE BICARBONATE RATIO" MENGGUNAKAN LUBANG RESAPAN BIOPORI : STUDI KASUS DI KOTA SEMARANG (Decreased of Sea Water Intrusion Based On “Chloride-Bicarbonater Ratio”Using the Biopore Absorption Hole

    Directory of Open Access Journals (Sweden)

    Siti Sundari Miswadi

    2010-11-01

    Hnya naik. Kadar N03 menunjukkan pada minggu ketiga dan minggu keenam didapatkan hasil yang sarna, yaitu 16,66% sumur naik, dan 83,30 % turun. Kadar PO43- pada minggu ketiga lerdeteksi sebesar 100% jumlah sumur turun, sedangkan pada minggu keenam 16,66% turun, dan 83,30 % naik. Nilai kekeruhan pada minggu ketiga terdeteksi 16,66% sumur naik, dan 83,30 % turun, sedangkan pada minggu keenam 49,98 % sumur naik kekeruhannya, dan 49,98 % turun. Berdasarkan hasil penelitian dapat disimpulkan, setelah penggunaan LRB pada minggu ketiga, sebanyak 82,41 % sumur mengalami penurunan dan 17,59% mengalami kenaikan pada ketujuh parameter, sedangkan pada minggu keenam sebanyak 54,75% sumur mengalami penurunan, dan 45,25 % sumur mengalami kenaikan pada ketujuh parameter. Hasil optimal penggunaan LRB sebagai adsorben diperoleh pada minggu keenam.   ABSTRACT Flood becomes annual agenda for the people who live in the coastal area of Semarang. But now, the regions which far from the coast are now no longer free from the flood and sea water intrusion. It happens because the water already exceeds the amount of soil replenishment (recharge, and the land has lost its function in absorbing water due to uncontrolled construction of buildings and housing which are not environmentally friendly. This study aims to map the level of sea water intrusion in the dug wells based on “Chloride-Bicarbonate Ratio”, and electrical conductivity (DHL and salinity in the city of Semarang. Research conducted on 30 dug wells owned by residents of the distance from the coast between 0,5-5 (five kilometers. Sea water intrusion rate was calculated based on the ratio of chloride to carbonate and bicarbonate, and the results were plotted on base maps. The results showed the level of sea water intrusion and the value of DHL in the eastern part of Semarang city much worse than the west coast area of Semarang, while the levels of salinity in most areas of research were in average levels. The results of studies

  16. Formation dynamics of subsurface hydrocarbon intrusions following the Deepwater Horizon blowout

    Science.gov (United States)

    Socolofsky, Scott A.; Adams, E. Eric; Sherwood, Christopher R.

    2011-01-01

    Hydrocarbons released following the Deepwater Horizon (DH) blowout were found in deep, subsurface horizontal intrusions, yet there has been little discussion about how these intrusions formed. We have combined measured (or estimated) observations from the DH release with empirical relationships developed from previous lab experiments to identify the mechanisms responsible for intrusion formation and to characterize the DH plume. Results indicate that the intrusions originate from a stratification-dominated multiphase plume characterized by multiple subsurface intrusions containing dissolved gas and oil along with small droplets of liquid oil. Unlike earlier lab measurements, where the potential density in ambient water decreased linearly with elevation, at the DH site it varied quadratically. We have modified our method for estimating intrusion elevation under these conditions and the resulting estimates agree with observations that the majority of the hydrocarbons were found between 800 and 1200 m.

  17. Numerical simulation and analysis of saltwater intrusion lengths in the Pearl River Delta, China

    NARCIS (Netherlands)

    Zhang, W.; Feng, H.; Zheng, J.; Hoitink, A.J.F.; Vegt, van der M.; Zhu, Y.; Cai, H.

    2013-01-01

    In recent years, large-scale saltwater intrusion has been threatening the freshwater supply in the metropolitan cities surrounding the Pearl River delta (PRD). Therefore, a better understanding of the saltwater intrusion process in this region is necessary for local water resource management. In thi

  18. Intrusion Detection using unsupervised learning

    Directory of Open Access Journals (Sweden)

    Kusum bharti

    2010-08-01

    Full Text Available Clustering is the one of the efficient datamining techniques for intrusion detection. In clustering algorithm kmean clustering is widely used for intrusion detection. Because it gives efficient results incase of huge datasets. But sometime kmean clustering fails to give best result because of class dominance problem and no class problem. So for removing these problems we are proposing two new algorithms for cluster to class assignment. According to our experimental results the proposed algorithm are having high precision and recall for low class instances.

  19. Building Intrusion Tolerant Software System

    Institute of Scientific and Technical Information of China (English)

    PENG Wen-ling; WANG Li-na; ZHANG Huan-guo; CHEN Wei

    2005-01-01

    In this paper, we describe and analyze the hypothesis about intrusion tolerance software system, so that it can provide an intended server capability and deal with the impacts caused by the intruder exploiting the inherent security vulnerabilities. We present some intrusion tolerance technology by exploiting N-version module threshold method in constructing multilevel secure software architecture, by detecting with hash value, by placing an "antigen" word next to the return address on the stack that is similar to human immune system, and by adding "Honey code" nonfunctional code to disturb intruder, so that the security and the availability of the software system are ensured.

  20. Effect of large-scale reservoir and river regulation/reclamation on saltwater intrusion in Qiantang Estuary

    Institute of Scientific and Technical Information of China (English)

    韩曾萃; 潘存鸿; 余炯; 程杭平

    2001-01-01

    By using field salinity data recorded in the Qiantang Estuary for the nearly forty years (which covers the periods before and after the erection of a large-scale reservoir in the watershed and river regulation/reclamation in the estuary) and one-dimensional salt water intrusion modeling, it is shown that the salt water intrusion decreases caused by increased low water discharge for the reservoir, while the intrusion increases for the increased tidal range because of the river regulation/reclamation. The integrate result is that the saltwater intrusion decreases.

  1. Study on coupling mathematical model of intrusion of sea water into canal and lake%海水入侵淡水运河与湖泊的耦合数学模型研究

    Institute of Scientific and Technical Information of China (English)

    姜治兵; 杨青远

    2015-01-01

    When ships pass through a lock in the canal that connects the rivers and sea, the salt in seawater would invade into the freshwater area by the density current to affect the regional water quality of freshwater area and the living environment of fresh-water aquatics. To analyze the saline exchange and transport characteristic during ship lock operation process, taking the pro-posed ship lock in Nicaragua Canal as the research object, we set up a coupling saline exchange model and three-dimension nu-merical model to simulate the step by step intrusion process of sea water into all step locks chambers and the further transportation into the upstream fresh water area. The simulation results show that salinity changes periodically in all step locks chambers and upstream waterway and reaches to a dynamic balance after a period of ship lock operation. The upstream saline transportation can be divided into density current section, transition section and diffusion section. Saline intrusion quantity in one cycle reduces gradually and trends to be steady with the operation time increasing. Based on the simulation results of coupling mathematical model, a differential equation is set up to predict the average salinity in Nicaragua Lake. The computing results show that the sa-linity of lake water in future is far less than salinity bearing capacity of environment.%江海连通运河中的船舶过闸时,海水中的盐分会在异重流作用下向淡水水域入侵,进而影响淡水水域的水质及淡水生物的生存环境. 为了分析船闸运行过程中盐分沿程交换与输运特征,以尼加拉瓜运河上的拟建船闸为例,通过建立耦合的盐分交换分析模型和三维数值模型,模拟计算了海水逐级入侵各级闸室并向上游淡水水域输运的过程. 模拟结果表明:各闸室与上游航道各断面的盐度呈周期性变化,在船闸运行一段时间后逐步趋于动态平衡;上游航道盐度输运可分为异重流段、过

  2. Tracking salinity intrusions in a coastal forested freshwater wetland system

    Science.gov (United States)

    Anand D. Jayakaran; Thomas M. Williams; William H. Conner

    2016-01-01

    Coastal forested freshwater wetlands are sentinel sites for salinity intrusions associated with large, tidally influenced, storm-driven or drought-induced incursions of estuarine waters into freshwater ecosystems. These incursions may also be exacerbated by rising sea levels associated with climate change.

  3. Net phytoplankton and zooplankton in the New York Bight, January 1976 to February 1978, with comments on the effects of wind, Gulf Stream eddies, and slope water intrusions

    OpenAIRE

    Smith, Daniel E.; Jossi, Jack W.

    1984-01-01

    Results are given of monthly net phytoplankton and zooplankton sampling from a 10 m depth in shelf, slope, and Gulf Stream eddy water along a transect running southeastward from Ambrose Light, New York, in 1976, 1977, and early 1978. Plankton abundance and temperature at 10 m and sea surface salinity at each station are listed. The effects of atmospheric forcing and Gulf Stream eddies on plankton distribution and abundance arc discussed. The frequency of Gulf Stream eddy passage through the N...

  4. INTEGRATED ASSESSMENTS OF POSSIBLE EFFECTS OF HYDROCARBON AND SALT WATER INTRUSION ON THE GROUNDWATER OF IGANMU AREA OF LAGOSMETROPOLIS, SOUTHWESTERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Adetayo F. Adetayo F.

    2010-06-01

    Full Text Available Vertical electrical sounding (VES and Induced Polarisation (IP methods of geophysical survey were incorporated with  physiochemical analysis of well water samples to determine vertical extent of petroleum-product contamination in subsurface soils and groundwater from bulk-fuel storage and distribution terminals in Iganmu area of Lagos. Interpreted results of VES and IP revealed four geoelectric layers. Clay with resistivity and IP values ranging from 1.5 - 14 m and 50 - 400mV/V respectively was encountered at the last layer penetrated by the survey except in four VES stations where the clay horizon was delineated at the third layer. This implies that subsurface aquifer is sealed by impervious layer which possibly prevents it from being contaminated by hydrocarbon and other refuse materials from the surface. Borehole log and electrical resistivity survey from a control site within the area were also incorporated with the geophysical measurements and these confirm lithologic similarity and the presence of a sealant above the aquifer layer. In addition to this, the results of the physical and geochemical analyses carried out on groundwater samples from shallow wells within the pack show very negligible level of hydrocarbon contamination which has no serious environmental implications on subsurface water in the area. However, electrical conductivity, salinity and TDS values obtained show high level of dissolved minerals (salts making the water highly saline and unsuitable for drinking being far above recommended values for drinking water. We thus inferred that Lagos lagoon must haveinvaded the aquifer in some places leading to high salinity observed.

  5. Geophysical prospecting method in intrusive rocks area fight a drought to find water wells set%物探方法在侵入岩地区抗旱找水定井中的应用

    Institute of Scientific and Technical Information of China (English)

    宋希利; 宋鹏; 田明阳; 彭玉明

    2012-01-01

    Intrusive rocks in the area of groundwater is difficult to find, but more abundant in the dry season the groundwater more difficult to find, to quickly resolve severe drought disaster in Shandong Yimcngshan people much-needed human and livestock water consumption through advanced and effective geophysical methods and reasonable working arrangement greatly increased drought in the intrusive rocks in the area to find water wells set the speed and rate guarantees as well, by the construction of drilling results verify the geophysical inference realistic, given the success rate of 96% well, single-well water yield are far beyond the estimated amount of water, to find a more extensive local groundwater resources, water resources needed to solve the problem of the masses, the people and the old liberated areas have been highly appreciated by the local government. Proved Yimengshan intrusive rocks in the area of geophysical methods based on different characteristics and be well area is difficult, easy, and CSAMT method were selected degree of resistivity sounding method to find underground water source not only improves the speed and success rate of well set, but also made good hydrogeological effects, it is in similar application areas. Practical work in the specific practice, one can not determine the geological survey of the ground target range and set well drilling difficult areas, the use of controlled source audio magnetotelluric: method is fast and efficient features, to sweep the work surface, suggesting that rock construction of fracture zone, delineated area that is rock crushing low resistance, water lots, and to determine the depth of drilling wells; the second is on the ground within the geological survey to determine, using the resistivity sounding method, the use of a single curve reflects the broken rocks, water section to determine the visual characteristics of the aquifer and depth.%侵入岩地区寻找地下水难度大,而在干旱季节找出较为

  6. A software tool for network intrusion detection

    CSIR Research Space (South Africa)

    Van der Walt, C

    2012-10-01

    Full Text Available This presentation illustrates how a recently developed software tool enables operators to easily monitor a network and detect intrusions without requiring expert knowledge of network intrusion detections....

  7. Non-Intrusive Appliance Recognition

    NARCIS (Netherlands)

    Hoogsteen, G; Hoogsteen, Gerwin; Krist, J.O.; Bakker, Vincent; Smit, Gerardus Johannes Maria

    2012-01-01

    Energy conservation becomes more important nowadays. The use of smart meters and, in the near future, smart appliances, are the key to achieve reduction in energy consumption. This research proposes a non-intrusive appliance monitor and recognition system for implementation on an embedded system. Th

  8. Occurrence of seawater intrusion overshoot

    NARCIS (Netherlands)

    Morgan, L.K.; Bakker, M.; Werner, A.D.

    2015-01-01

    A number of numerical modeling studies of transient sea level rise (SLR) and seawater intrusion (SI) in flux-controlled aquifer systems have reported an overshoot phenomenon, whereby the freshwater-saltwater interface temporarily extends further inland than the eventual steady state position. Recent

  9. Final OSWER Vapor Intrusion Guidance

    Science.gov (United States)

    EPA is preparing to finalize its guidance on assessing and addressing vapor intrusion, which is defined as migration of volatile constituents from contaminated media in the subsurface (soil or groundwater) into the indoor environment. In November 2002, EPA issued draft guidance o...

  10. Experiences with network intrusion detection

    NARCIS (Netherlands)

    Coolen, R.; Luiijf, H.A.M.; Geloven, W.J.F. van; Bakker, E.A.

    2002-01-01

    This paper describes our experience with several commercial Network Intrusion Detection Systems (NIDSs)deployed in a network connected to the Internet. Specific problems in the operation of NIDS are highlighted, and a number of solutions to identified problems will be presented. Finally, we shall pr

  11. Intrusive luxation of 60 permanent incisors

    DEFF Research Database (Denmark)

    Tsilingaridis, Georgios; Malmgren, Barbro; Andreasen, Jens O;

    2012-01-01

    Intrusive luxation in the permanent dentition is an uncommon injury but it is considered one of the most severe types of dental trauma because of the risk for damage to the periodontal ligament, pulp and alveolar bone. Management of intrusive luxation in the permanent dentition is controversial....... The purpose of this study was to evaluate pulp survival and periodontal healing in intrusive luxated permanent teeth in relation to treatment alternatives, degree of intrusion and root development....

  12. Excess water generation during reaction-inducing intrusion of granitic melts into ultramafic rocks at crustal P-T conditions in the Sør Rondane Mountains of East Antarctica

    Science.gov (United States)

    Uno, Masaoki; Okamoto, Atsushi; Tsuchiya, Noriyoshi

    2017-07-01

    Arc magmas are one of the main sources of aqueous geofluids in the crust, and the movement of fluids above magma chambers has been geophysically imaged. Here, we constrain the water budget (i.e., supply, consumption and release of H2O) in these areas above magma chamber by examining the hydration caused by crust-melt reactions in the Sør Rondane Mountains of East Antarctica. The study area contains a phlogopite-pargasite-peridotite unit that has been intruded by numerous granitic dikes, creating hydration reaction zones at the dike-peridotite boundary. These reactions occurred at 0.5 GPa and 700 °C, corresponding to middle crustal conditions, and generated a series of reaction zones with distance from the granitic dikes as follows: (i) granitic dike, (ii) pargasite-actinolite zone, (iii) tremolite-phlogopite zone, (iv) anthophyllite-phlogopite zone, (v) phlogopite-olivine-orthopyroxene zone, and (vi) unaltered pargasite-phlogopite peridotite. The presence of amphiboles with a preferred orientation perpendicular to the dike margins and an absence of Cr-rich magnetite indicate that the pargasite-actinolite zone [zone (ii)] grew from the dike margins as a result of the dike reacting with the host rock, with an initial melt/rock boundary located between zones (ii) and (iii). The H2O contents of reaction zones (ii)-(v) are higher than the content in the hosting pargasite-phlogopite peridotite, suggesting that the intrusion of the dike was associated with hydration reactions. Geochemical analysis along a profile through the reaction zones indicates Mg and Fe depletion, and Si enrichment in zones (iii)-(iv), and Ca depletion and K enrichment in zones (iv)-(v) relative to the hosting pargasite-phlogopite peridotite. In contrast, zone (ii) is characterized by Ca, Fe, and Mg enrichments relative to the granitic dike. These observations suggest that the reaction zone sequence was formed by the elemental transfer between granitic dike and parasite-phlogopite peridotite: Ca

  13. Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

    DEFF Research Database (Denmark)

    Joergensen, F.; Scheer, W.; Thomsen, S.

    2012-01-01

    revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing....../freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still...

  14. How stratospheric are deep stratospheric intrusions? LUAMI 2008

    Science.gov (United States)

    Trickl, Thomas; Vogelmann, Hannes; Fix, Andreas; Schäfler, Andreas; Wirth, Martin; Calpini, Bertrand; Levrat, Gilbert; Romanens, Gonzague; Apituley, Arnoud; Wilson, Keith M.; Begbie, Robert; Reichardt, Jens; Vömel, Holger; Sprenger, Michael

    2016-07-01

    A large-scale comparison of water-vapour vertical-sounding instruments took place over central Europe on 17 October 2008, during a rather homogeneous deep stratospheric intrusion event (LUAMI, Lindenberg Upper-Air Methods Intercomparison). The measurements were carried out at four observational sites: Payerne (Switzerland), Bilthoven (the Netherlands), Lindenberg (north-eastern Germany), and the Zugspitze mountain (Garmisch-Partenkichen, German Alps), and by an airborne water-vapour lidar system creating a transect of humidity profiles between all four stations. A high data quality was verified that strongly underlines the scientific findings. The intrusion layer was very dry with a minimum mixing ratios of 0 to 35 ppm on its lower west side, but did not drop below 120 ppm on the higher-lying east side (Lindenberg). The dryness hardens the findings of a preceding study ("Part 1", Trickl et al., 2014) that, e.g., 73 % of deep intrusions reaching the German Alps and travelling 6 days or less exhibit minimum mixing ratios of 50 ppm and less. These low values reflect values found in the lowermost stratosphere and indicate very slow mixing with tropospheric air during the downward transport to the lower troposphere. The peak ozone values were around 70 ppb, confirming the idea that intrusion layers depart from the lowermost edge of the stratosphere. The data suggest an increase of ozone from the lower to the higher edge of the intrusion layer. This behaviour is also confirmed by stratospheric aerosol caught in the layer. Both observations are in agreement with the idea that sections of the vertical distributions of these constituents in the source region were transferred to central Europe without major change. LAGRANTO trajectory calculations demonstrated a rather shallow outflow from the stratosphere just above the dynamical tropopause, for the first time confirming the conclusions in "Part 1" from the Zugspitze CO observations. The trajectories qualitatively explain

  15. Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

    Directory of Open Access Journals (Sweden)

    F. Jørgensen

    2012-03-01

    Full Text Available Geophysical techniques are increasingly used as tools for characterising the subsurface and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark a combination of an airborne transient electromagnetic survey (performed with the SkyTEM system, a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m giving a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, deep and shallow buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological elements mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area thus providing important information on the fresh-saltwater boundary and the chemical status of groundwater. Although, the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore is strongly influenced by the increased electrical conductivity here, buried valleys and other geological elements are still revealed. The salinity distribution indicates preferential flow paths through and along specific geological elements within the area. The effects of future sea level rise on the groundwater system and chemical status are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and assessing their control on the groundwater salinity distribution.

  16. Transboundary geophysical mapping of geological elements and salinity distribution critical for the assessment of future sea water intrusion in response to sea level rise

    Directory of Open Access Journals (Sweden)

    F. Jørgensen

    2012-07-01

    Full Text Available Geophysical techniques are increasingly being used as tools for characterising the subsurface, and they are generally required to develop subsurface models that properly delineate the distribution of aquifers and aquitards, salt/freshwater interfaces, and geological structures that affect groundwater flow. In a study area covering 730 km2 across the border between Germany and Denmark, a combination of an airborne electromagnetic survey (performed with the SkyTEM system, a high-resolution seismic survey and borehole logging has been used in an integrated mapping of important geological, physical and chemical features of the subsurface. The spacing between flight lines is 200–250 m which gives a total of about 3200 line km. About 38 km of seismic lines have been collected. Faults bordering a graben structure, buried tunnel valleys, glaciotectonic thrust complexes, marine clay units, and sand aquifers are all examples of geological structures mapped by the geophysical data that control groundwater flow and to some extent hydrochemistry. Additionally, the data provide an excellent picture of the salinity distribution in the area and thus provide important information on the salt/freshwater boundary and the chemical status of groundwater. Although the westernmost part of the study area along the North Sea coast is saturated with saline water and the TEM data therefore are strongly influenced by the increased electrical conductivity there, buried valleys and other geological elements are still revealed. The mapped salinity distribution indicates preferential flow paths through and along specific geological structures within the area. The effects of a future sea level rise on the groundwater system and groundwater chemistry are discussed with special emphasis on the importance of knowing the existence, distribution and geometry of the mapped geological elements, and their control on the groundwater salinity distribution is assessed.

  17. Osmotic pressure effects upon intrusion of liquid electrolytes inside hydrophobic MOF's

    CERN Document Server

    Michelin-Jamois, M; Charlaix, E; Vigier, G

    2014-01-01

    High pressure water intrusion in hydrophobic nanoporous media have been studied in relation with energy storage. It has already been showed that addition of electrolytes in water increases intrusion pressure of liquid leading to an enhancement of storing capacities. We demonstrate here that for a number of salt, a very simple van't Hoff law can explain intrusion and extrusion excess pressures compared with the pure water case. Our results suggest that only pure water can penetrate the pores, the ions being quartered in the bulk liquid around nanoporous medium. This selectivity explains very high pressures for very concentrated ions reported by Tzanis et al (2014). Finally, a partial intrusion of NaI and LiI is observed. This effect could be explained on the basis of particular behaviour or iodide ions over hydrophobic surfaces.

  18. Misleading reconstruction of seawater intrusion via integral depth sampling

    Science.gov (United States)

    Colombani, N.; Volta, G.; Osti, A.; Mastrocicco, M.

    2016-05-01

    Saltwater intrusion in coastal aquifers is an urgent issue for the actual and future groundwater supply and a detailed characterization of groundwater quality with depth is a fundamental prerequisite to correctly distinguish salinization processes. In this study, interpolated Cl- maps of the Po River delta coastal aquifer (Italy), gained with Integrated Depth Sampling (IDS) and Multi-Level Sampling (MLS) techniques, are compared. The data set used to build up the IDS and MLS interpolated Cl- maps come from numerous monitoring campaigns on surface and ground waters, covering the time frame from 2010 to 2014. The IDS interpolated Cl- map recalls the phenomenon of actual seawater intrusion, with Cl- concentration never exceeding that of seawater and the absence of hypersaline groundwater all over the study area. On the contrary, in the MLS interpolated Cl- maps the lower portion of the unconfined aquifer presents hypersaline groundwater making it necessary to consider salinization processes other than actual seawater intrusion, like upward flux from a saline aquitard. Results demonstrate the obligation of using MLS in reconstructing a reliable representation of the distribution of salinity, especially in areas where the density contrast between fresh and saline groundwater is large. Implications of the reported field case are not limited to the local situation but have a wider significance, since the IDS technique is often employed in saltwater intrusion monitoring even in recent works, with detrimental effect on the sustainable water resource management of coastal aquifers.

  19. Classification and Importance of Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    Rajasekaran K

    2012-08-01

    Full Text Available An intrusion detection system (IDS is a device or software application that monitors network or system activities for malicious activities or policy violations and produces reports to a Management Station. Some systems may attempt to stop an intrusion attempt but this is neither required nor expected of a monitoring system. Due to a growing number of intrusion events and also because the Internet and local networks have become so ubiquitous, organizations are increasingly implementing various systems that monitor IT security breaches. This includes an overview of the classification of intrusion detection systems and introduces the reader to some fundamental concepts of IDS methodology: audit trail analysis and on-the-fly processing as well as anomaly detection and signature detection approaches. This research paper discusses the primary intrusion detection techniques and the classification of intrusion Detection system.

  20. Association Rules Applied to Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We discuss the basic intrusion detection techniques, and focus on how to apply association rules to intrusion detection. Begin with analyzing some close relations between user's behaviors, we discuss the mining algorithm of association rules and apply to detect anomaly in IDS. Moreover, according to the characteristic of intrusion detection, we optimize the mining algorithm of association rules, and use fuzzy logic to improve the system performance.

  1. Chlorinity distribution and water intake operation of the Chenhang Reservoir during saltwater intrusions in the Yangtze Estuary%陈行水库在长江河口咸潮入侵期间的取水调度和库内氯度分布

    Institute of Scientific and Technical Information of China (English)

    申一尘; 李路; 朱建荣

    2012-01-01

    In order to supply water during severe saltwater intrusions in the Yangtze Estuary, the Chenhang Reservoir sometimes took brackish water. The chlorinity in the reservoir was measured during November 27 in 2009 to March 12 in 2010. Combined with the river discharge, water level, wind stress, chlorinity at the upstream station and its inlet,the saltwater intrusion in the estuary, the way of water intake operation, and temporal/spatial variations of the chlorinity in the reservoir were analyzed. The simulated results showed that, the upstream was tended to be present around its eastern coastline under westward wind. Before the brackish water reached the reservoir, the amount of the water intake was increased to make it to high water lev-el. At the beginning of a saltwater intrusion, the reservoir took the brackish water to keep its higher water level. In the later of the saltwater intrusion, some freshwater was taken from the Baogang Reservoir and the amount depended on the intensity of saltwater intrusion. Furthermore, the water intake from the Yangtze River must be paused when the chlorinity at the supply outlet in the reservoir was close to 250 mg/L. The measured data indicated that the chlorinity of the reservoir was increased when the brackish water in-taking was conducted and experienced a spatial variation under different wind stresses. The water intake operation of the Chenhang Reservoir was dependent on the chlorinity inside/outside it. In addition, its water level, the chtorini-ty in its upstream as well as the wind stress should also be taken into account. This study can bring experience to the reservoirs built in estuaries for better operation.%在长江河口咸潮入侵严重期间,为保证供水,陈行水库有时会带盐取水.2009年11月27日至2010年3月12日在陈行水库进行了氯度观测.结合径流量、潮汐、风应力、上游氯度和取水口氯度,分析了长江河口咸潮入侵以及陈行水库3次带盐取水的运行方式

  2. Non-intrusive refractometer sensor

    Indian Academy of Sciences (India)

    Pabitra Nath

    2010-04-01

    An experimental realization of a simple non-intrusive refractometer sensor is demonstrated in this communication. The working principle of the sensor is based on intensity modulation of the back-reflected light when output light from an optical fibre end focusses onto air–medium interface. The change in the refractive index of the medium affects the reflectance of the incident light signal and thus modulates the back-reflected signal. Refractive index variation as small as 0.002 RIU can be measured using the present technique. The advantages of the technique are its simplicity, cost efficiency and usefulness in monitoring refractive indices of acidic solutions.

  3. Predicting The Intrusion Layer From Deep Ocean Oil Spills

    Science.gov (United States)

    Wang, Dayang; Chow, Aaron; Adams, E. Eric

    2015-11-01

    Oil spills from deep ocean blowout events motivate our study of multiphase plumes in a water column. Key to understanding the long-term fate of these plumes is the ability to predict the depth and persistence of intrusion layers. While intrusion layers from multiphase plumes have been studied under stagnant conditions, their behavior in the presence of crossflow, especially in mild crossflow, remains poorly understood. The classical classification of plume behavior identifies two regimes: crossflow-dominant and stratification-dominant--but it does not account for the interplay between the two effects, leaving the transition region unexplored. We conduct laboratory tank experiments to investigate the behavior of intrusion layers under the simultaneous action of crossflow and stratification. Our experiments use an inverted frame of reference, using glass beads with a range of sizes to simulate oil droplets. We find that crossflow creates enhanced mixing, which in turn leads to a shallower intrusion layer of the released fluid (correspondingly, a deeper layer in the case of a deep ocean blowout). We develop a mathematical formulation that extends previous models to account for crossflow effects, and use field observations to validate the analytical and experimental findings.

  4. Sulfide intrusion and detoxification in Zostera marina

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    2014-01-01

    nutrition in general. By a global review of sulfide intrusion, coupled with a series of field studies and in situ experiments we elucidate sulfide intrusion and different strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis...... indicating a possible role of sulfide in the sulfur nutrition beside the detoxification function. Our results suggest different adaptations of Z. marina to reduced sediments and sulfide intrusion ranging from bacterial and chemical reoxidation of sulfide to sulfate to incorporation of sulfide into organic...

  5. An international perspective on Facebook intrusion.

    Science.gov (United States)

    Błachnio, Agata; Przepiorka, Aneta; Benvenuti, Martina; Cannata, Davide; Ciobanu, Adela Magdalena; Senol-Durak, Emre; Durak, Mithat; Giannakos, Michail N; Mazzoni, Elvis; Pappas, Ilias O; Popa, Camelia; Seidman, Gwendolyn; Yu, Shu; Wu, Anise M S; Ben-Ezra, Menachem

    2016-08-30

    Facebook has become one of the most popular social networking websites in the world. The main aim of the study was to present an international comparison of Facebook intrusion and Internet penetration while examining possible gender differences. The study consisted of 2589 participants from eight countries: China, Greece, Israel, Italy, Poland, Romania, Turkey, USA. Facebook intrusion and Internet penetration were taken into consideration. In this study the relationship between Facebook intrusion and Internet penetration was demonstrated. Facebook intrusion was slightly negatively related to Internet penetration in each country.

  6. Relationship between vapor intrusion and human exposure to trichloroethylene

    OpenAIRE

    ARCHER, NATALIE P.; BRADFORD, CARRIE M.; VILLANACCI, JOHN F.; CRAIN, NEIL E.; Corsi, Richard L; Chambers, David M.; BURK, TONIA; Blount, Benjamin C.

    2015-01-01

    Trichloroethylene (TCE) in groundwater has the potential to volatilize through soil into indoor air where it can be inhaled. The purpose of this study was to determine whether individuals living above TCE-contaminated groundwater are exposed to TCE through vapor intrusion. We examined associations between TCE concentrations in various environmental media and TCE concentrations in residents. For this assessment, indoor air, outdoor air, soil gas, and tap water samples were collected in and aro...

  7. Animal intrusion status report for fiscal year 1989

    Energy Technology Data Exchange (ETDEWEB)

    Landeen, D.S.

    1990-08-01

    The Protective Barrier and Warning Marker System Development Plan identified tasks that need to be completed to design a final protective barrier to implement in-place disposal of radioactive waste. This report summarizes the animal intrusion tasks that were conducted by Westinghouse Hanford Company in fiscal years 1988 and 1989 with respect to small mammals and water infiltration. 2 refs., 8 figs., 6 tabs.

  8. Intrusive and Non-Intrusive Load Monitoring (A Survey

    Directory of Open Access Journals (Sweden)

    Marco Danilo Burbano Acuña

    2015-05-01

    Full Text Available There is not discussion about the need of energyconservation, it is well known that energy resources are limitedmoreover the global energy demands will double by the end of2030, which certainly will bring implications on theenvironment and hence to all of us.Non-Intrusive load monitoring (NILM is the process ofrecognize electrical devices and its energy consumption basedon whole home electric signals, where this aggregated load datais acquired from a single point of measurement outside thehousehold. The aim of this approach is to get optimal energyconsumption and avoid energy wastage. Intrusive loadmonitoring (ILM is the process of identify and locate singledevices through the use of sensing systems to support control,monitor and intervention of such devices. The aim of thisapproach is to offer a base for the development of importantapplications for remote and automatic intervention of energyconsumption inside buildings and homes as well. For generalpurposes this paper states a general framework of NILM andILM approaches.Appliance discerns can be tackled using approaches fromdata mining and machine learning, finding out the techniquesthat fit the best this requirements, is a key factor for achievingfeasible and suitable appliance load monitoring solutions. Thispaper presents common and interesting methods used.Privacy concerns have been one of the bigger obstacles forimplementing a widespread adoption of these solutions; despitethis fact, developed countries like those inside the EU and theUK have established a deadline for the implementation ofsmart meters in the whole country, whereas USA governmentstill struggles with the acceptance of this solution by itscitizens.The implementation of security over these approachesalong with fine-grained energy monitoring would lead to abetter public agreement of these solutions and hence a fasteradoption of such approaches. This paper reveals a lack ofsecurity over these approaches with a real scenario.

  9. Vapour Intrusion into Buildings - A Literature Review

    Science.gov (United States)

    This chapter provides a review of recent research on vapour intrusion of volatile organic compounds (VOCs) into buildings. The chapter builds on a report from Tillman and Weaver (2005) which reviewed the literature on vapour intrusion through 2005. Firstly, the term ‘vapour intru...

  10. 后三峡工程时代长江口水源地盐水入侵规律及其应对措施%Saltwater intrusion into water source zone in Yangtze Estuary in post-Three Gorges engineering era and countermeasures

    Institute of Scientific and Technical Information of China (English)

    陈祖军

    2014-01-01

    Based on the main impact factors and features of saltwater intrusion in the Yangtze Estuary , the variations of the annual and monthly average runoff at the Datong Hydrological Station on the Yangtze River since the beginning of operation of the Three Gorges Reservoir were analyzed .The characteristics of typical wet years , normal years , and dry years are shown in the lower reaches of the Yangtze River with significant seasonal variations.Meanwhile, the features of saltwater intrusion into the water source zone in the Yangtze Estuary in the era after the beginning of Three Gorges engineering were studied .The results show that , in dry seasons , the saltwater intrusion into the water source zone had a relatively close correlation with the daily runoff at the Datong Hydrological Station six days prior to the first day on which the intrusion occurred .The impact of saltwater intrusion can usually be seen from September to the following April , and especially in February , according to the Chinese lunar calendar .The chloride concentration peak showed a double hump-shaped distribution on the 8 th and the 22 nd of each lunar month .Some suggestions are given for reducing the impacts of saltwater intrusion in the Yangtze Estuary on the water supply safety in the water source zone of Shanghai City .These suggestions include promoting cooperation and sharing of information between river basin administrations and local departments , jointly building the controlling projects on the north branch of the Yangtze Estuary , and co-developing the water source zones ( reservoirs) in the Yangtze Estuary .%在简述长江口盐水入侵主要影响要素与特性的基础上,对三峡水库运行以来长江大通水文站年径流量、月径流量的变化规律进行了简析,发现长江下游仍呈现典型丰、平、枯水年特征,其季节变化规律也十分显著。同时对后三峡工程时代的长江口水源地盐水入侵特征进行了研究,结果表

  11. Potential for saltwater intrusion into the lower Tamiami aquifer near Bonita Springs, southwestern Florida

    Science.gov (United States)

    Shoemaker, W. Barclay; Edwards, K. Michelle

    2003-01-01

    A study was conducted to examine the potential for saltwater intrusion into the lower Tamiami aquifer beneath Bonita Springs in southwestern Florida. Field data were collected, and constant- and variable-density ground-water flow simulations were performed that: (1) spatially quantified modern and seasonal stresses, (2) identified potential mechanisms of saltwater intrusion, and (3) estimated the potential extent of saltwater intrusion for the area of concern. MODFLOW and the inverse modeling routine UCODE were used to spatially quantify modern and seasonal stresses by calibrating a constant-density ground-water flow model to field data collected in 1996. The model was calibrated by assuming hydraulic conductivity parameters were accurate and by estimating unmonitored ground-water pumpage and potential evapotranspiration with UCODE. Uncertainty in these estimated parameters was quantified with 95-percent confidence intervals. These confidence intervals indicate more uncertainty (or less reliability) in the estimates of unmonitored ground-water pumpage than estimates of pan-evaporation multipliers, because of the nature and distribution of observations used during calibration. Comparison of simulated water levels, streamflows, and net recharge with field data suggests the model is a good representation of field conditions. Potential mechanisms of saltwater intrusion into the lower Tamiami aquifer include: (1) lateral inland movement of the freshwater-saltwater interface from the southwestern coast of Florida; (2) upward leakage from deeper saline water-bearing zones through natural upwelling and upconing, both of which could occur as diffuse upward flow through semiconfining layers, conduit flow through karst features, or pipe flow through leaky artesian wells; (3) downward leakage of saltwater from surface-water channels; and (4) movement of unflushed pockets of relict seawater. Of the many potential mechanisms of saltwater intrusion, field data and variable

  12. Intrusion Preventing System using Intrusion Detection System Decision Tree Data Mining

    Directory of Open Access Journals (Sweden)

    Syurahbil

    2009-01-01

    Full Text Available Problem statement: To distinguish the activities of the network traffic that the intrusion and normal is very difficult and to need much time consuming. An analyst must review all the data that large and wide to find the sequence of intrusion on the network connection. Therefore, it needs a way that can detect network intrusion to reflect the current network traffics. Approach: In this study, a novel method to find intrusion characteristic for IDS using decision tree machine learning of data mining technique was proposed. Method used to generate of rules is classification by ID3 algorithm of decision tree. Results: These rules can determine of intrusion characteristics then to implement in the firewall policy rules as prevention. Conclusion: Combination of IDS and firewall so-called the IPS, so that besides detecting the existence of intrusion also can execute by doing deny of intrusion as prevention.

  13. The evolution process of seawater intrusion in Laizhou Bay, and its linkage to climate change and human activity

    Science.gov (United States)

    xu, X.

    2013-12-01

    Seawater Intrusion is that seawater or saltwater intrude into the continent along the aquifer.Under the effects of the natural and artificial factors, the hydrodynamic conditions of aquifer in the coastal area has been changed ,which break the equilibrium between the seawater and the freshwater, hence the salt-fresh interface moves on the continent. Sea-level rise due to climate change and the paleoseawater hosting in marine strata combined with a rising population density in the Laizhou Bay have led to higher stresses on coastal water resources, and the risk of seawater intrusion has increased. Despite comprehensive seawater intrusion research and prevention measures are developed, the effects of climate change and human activity on seawater intrusion is still unclear. Therefore to reveal how climate change and human activity impact on seawater intrusion and to mathematical quantify it is important to establish reasonable prevention and control of seawater intrusion measures. Laizhou Bay is the region suffering from the geo-hazard of sea (saline) water intrusion most seriously in China, and is divided into seawater intrusion area, saline water (paleo-sea water) intrusion area and sea-saline water intrusion area The area of seawter intrusion in Laizhou Bay nearly 4,000 km2. And the seawater intrusion disasters in Laizhou bay can be divided into five stage from 1976 to now, which is Initial stage (1976-1979),Developing stage (1980-1985), Deterioration stage(1987-1989), Release stage (1990-2000)and Differentiation stage (2000-). The impact of human activities is shown as seawater intrusion in the linear growth trend. With the rapid economic development, the increase in abstraction from aquifers results in a serious imbalance between the seawater and freshwater interface, and the risk of seawater intrusion has increased. Taking into account of the climate change and human activity factors and seawater intrusion evaluation factors, such as the intensity of Cl

  14. Effects of recharge wells and flow barriers on seawater intrusion.

    Science.gov (United States)

    Luyun, Roger; Momii, Kazuro; Nakagawa, Kei

    2011-01-01

    The installation of recharge wells and subsurface flow barriers are among several strategies proposed to control seawater intrusion on coastal groundwater systems. In this study, we performed laboratory-scale experiments and numerical simulations to determine the effects of the location and application of recharge wells, and of the location and penetration depth of flow barriers, on controlling seawater intrusion in unconfined coastal aquifers. We also compared the experimental results with existing analytical solutions. Our results showed that more effective saltwater repulsion is achieved when the recharge water is injected at the toe of the saltwater wedge. Point injection yields about the same repulsion compared with line injection from a screened well for the same recharge rate. Results for flow barriers showed that more effective saltwater repulsion is achieved with deeper barrier penetration and with barriers located closer to the coast. When the flow barrier is installed inland from the original toe position however, saltwater intrusion increases with deeper barrier penetration. Saltwater repulsion due to flow barrier installation was found to be linearly related to horizontal barrier location and a polynomial function of the barrier penetration depth. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

  15. Corrosion inhibitor development for slightly sour environments with oxygen intrusion

    Energy Technology Data Exchange (ETDEWEB)

    Wylde, J.; Wang, H.; Li, J. [Clariant Oil Services North America, Calgary, AB (Canada)

    2009-07-01

    This presentation reported on a study that examined the effect of oxygen on the inhibition of carbon steel in slightly sour corrosion, and the initiation and propagation of localized attack. Oxygen can enter sour water injection systems through the vapor space in storage tanks and process system. Oxygen aggravates the corrosion attack by participating in the cathodic reaction under full or partial diffusion control. Laboratory testing results were reported in this presentation along with the development of corrosion inhibitors for such a slightly sour system. Bubble testing cells were used with continuous H{sub 2}/CO{sub 2} mixture gas sparging and occasional oxygen intrusion of 2 to 4 hours during a week long test. Linear polarization resistance (LPR) measurements and weight loss corrosion coupons were used to quantify the corrosion attack. The findings were presented in terms of the magnitude of localized attacks at different oxygen concentrations and intrusion periods, with and without the presence of corrosion inhibitors. tabs., figs.

  16. Geochemical and isotopic signatures for the identification of seawater intrusion in an alluvial aquifer

    Indian Academy of Sciences (India)

    Indu S Nair; S P Rajaveni; M Schneider; L Elango

    2015-08-01

    Seawater intrusion is one of the alarming processes that reduces the water quality and imperils the supply of freshwater in coastal aquifers. The region, north of the Chennai city, India is one such site affected by seawater intrusion. The objective of this study is to identify the extent of seawater intruded area by major geochemical and isotopic signatures. A total of 102 groundwater samples were collected and analysed for major and minor ions. Groundwater samples with electrical conductivity (EC) greater than 5000 S/cm and a river mouth sample were analyzed for Oxygen-18 (18O) and Deuterium (2H) isotopes to study their importance in monitoring seawater intrusion. The molar ratio of geochemical indicators and isotopic signatures suggests an intrusion up to a distance of 13 km from the sea as on March 2012 and up to 14.7 km during May 2012.

  17. Signature Based Intrusion Detection System Using SNORT

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2012-11-01

    Full Text Available Now a day’s Intrusion Detection systems plays very important role in Network security. As the use of internet is growing rapidly the possibility of attack is also increasing in that ratio. People are using signature based IDS’s. Snort is mostly used signature based IDS because of it is open source software. World widely it is used in intrusion detection and prevention domain. Basic analysis and security engine (BASE is also used to see the alerts generated by Snort. In the paper we have implementation the signature based intrusion detection using Snort. Our work will help to novel user to understand the concept of Snort based IDS.

  18. Grey-theory based intrusion detection model

    Institute of Scientific and Technical Information of China (English)

    Qin Boping; Zhou Xianwei; Yang Jun; Song Cunyi

    2006-01-01

    To solve the problem that current intrusion detection model needs large-scale data in formulating the model in real-time use, an intrusion detection system model based on grey theory (GTIDS) is presented. Grey theory has merits of fewer requirements on original data scale, less limitation of the distribution pattern and simpler algorithm in modeling.With these merits GTIDS constructs model according to partial time sequence for rapid detect on intrusive act in secure system. In this detection model rate of false drop and false retrieval are effectively reduced through twice modeling and repeated detect on target data. Furthermore, GTIDS framework and specific process of modeling algorithm are presented. The affectivity of GTIDS is proved through emulated experiments comparing snort and next-generation intrusion detection expert system (NIDES) in SRI international.

  19. Intrusion Detection Architecture Utilizing Graphics Processors

    Directory of Open Access Journals (Sweden)

    Branislav Madoš

    2012-12-01

    Full Text Available With the thriving technology and the great increase in the usage of computer networks, the risk of having these network to be under attacks have been increased. Number of techniques have been created and designed to help in detecting and/or preventing such attacks. One common technique is the use of Intrusion Detection Systems (IDS. Today, number of open sources and commercial IDS are available to match enterprises requirements. However, the performance of these systems is still the main concern. This paper examines perceptions of intrusion detection architecture implementation, resulting from the use of graphics processor. It discusses recent research activities, developments and problems of operating systems security. Some exploratory evidence is presented that shows capabilities of using graphical processors and intrusion detection systems. The focus is on how knowledge experienced throughout the graphics processor inclusion has played out in the design of intrusion detection architecture that is seen as an opportunity to strengthen research expertise.

  20. Autonomous Rule Creation for Intrusion Detection

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Jim Alves-Foss; Milos Manic

    2011-04-01

    Many computational intelligence techniques for anomaly based network intrusion detection can be found in literature. Translating a newly discovered intrusion recognition criteria into a distributable rule can be a human intensive effort. This paper explores a multi-modal genetic algorithm solution for autonomous rule creation. This algorithm focuses on the process of creating rules once an intrusion has been identified, rather than the evolution of rules to provide a solution for intrusion detection. The algorithm was demonstrated on anomalous ICMP network packets (input) and Snort rules (output of the algorithm). Output rules were sorted according to a fitness value and any duplicates were removed. The experimental results on ten test cases demonstrated a 100 percent rule alert rate. Out of 33,804 test packets 3 produced false positives. Each test case produced a minimum of three rule variations that could be used as candidates for a production system.

  1. Periodontal changes following molar intrusion with miniscrews

    Directory of Open Access Journals (Sweden)

    Shahin Bayani

    2015-01-01

    Conclusion: Within the limitations of this study, these results suggest that not only periodontal status was not negatively affected by intrusion, but also there were signs of periodontal improvement including attachment gain and shortening of clinical crown height.

  2. Autonomous Rule Creation for Intrusion Detection

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Jim Alves-Foss; Milos Manic

    2011-04-01

    Many computational intelligence techniques for anomaly based network intrusion detection can be found in literature. Translating a newly discovered intrusion recognition criteria into a distributable rule can be a human intensive effort. This paper explores a multi-modal genetic algorithm solution for autonomous rule creation. This algorithm focuses on the process of creating rules once an intrusion has been identified, rather than the evolution of rules to provide a solution for intrusion detection. The algorithm was demonstrated on anomalous ICMP network packets (input) and Snort rules (output of the algorithm). Output rules were sorted according to a fitness value and any duplicates were removed. The experimental results on ten test cases demonstrated a 100 percent rule alert rate. Out of 33,804 test packets 3 produced false positives. Each test case produced a minimum of three rule variations that could be used as candidates for a production system.

  3. A phased approach to network intrusion detection

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, K.A.; DuBois, D.H.; Stallings, C.A.

    1991-01-01

    This paper describes the design and development of a prototype intrusion detection system for the Los Alamos National Laboratory's Integrated Computing Network (ICN). The development of this system is based on three basic assumptions: (1) that statistical analysis of computer system and user activates may be used to characterize normal system and user behavior, and that given the resulting statistical profiles, behavior which deviates beyond certain bounds can be detected, (2) that expert system techniques can be applied to security auditing and intrusion detection, and (3) that successful intrusion detection may take place while monitoring a limited set of network activities. The Network Anomaly Detection and Intrusion Reporter (NADIR) design intent was to duplicate and improve the audit record review activities which had previously been undertaken by security personnel, to replace the manual review of audit logs with a near realtime expert system.

  4. Immune Based Intrusion Detector Generating Algorithm

    Institute of Scientific and Technical Information of China (English)

    DONG Xiao-mei; YU Ge; XIANG Guang

    2005-01-01

    Immune-based intrusion detection approaches are studied. The methods of constructing self set and generating mature detectors are researched and improved. A binary encoding based self set construction method is applied. First,the traditional mature detector generating algorithm is improved to generate mature detectors and detect intrusions faster. Then, a novel mature detector generating algorithm is proposed based on the negative selection mechanism. Accord ing to the algorithm, less mature detectors are needed to detect the abnormal activities in the network. Therefore, the speed of generating mature detectors and intrusion detection is improved. By comparing with those based on existing algo rithms, the intrusion detection system based on the algorithm has higher speed and accuracy.

  5. A Citizen's Guide to Vapor Intrusion Mitigation

    Science.gov (United States)

    This guide describes how vapor intrusion is the movement of chemical vapors from contaminated soil and groundwater into nearby buildings.Vapors primarily enter through openings in the building foundation or basement walls.

  6. Intrusion Detection System Using Advanced Honeypots

    CERN Document Server

    Singh, Ram Kumar

    2009-01-01

    The exponential growth of Internet traffic has made public servers increasingly vulnerable to unauthorized accesses and intrusions. In addition to maintaining low latency for the client, filtering unauthorized accesses has become one of the major concerns of a server maintainer. This implementation of an Intrusion Detection System distinguishes between the traffic coming from clients and the traffic originated from the attackers, in an attempt to simultaneously mitigate the problems of both latency and security. We then present the results of a series of stress and scalability tests, and suggest a number of potential uses for such a system. As computer attacks are becoming more and more difficult to identify the need for better and more efficient intrusion detection systems increases. The main problem with current intrusion detection systems is high rate of false alarms. Using honeypots provides effective solution to increase the security.

  7. IGNEOUS INTRUSION IMPACTS ON WASTE PACKAGES AND WASTE FORMS

    Energy Technology Data Exchange (ETDEWEB)

    P. Bernot

    2004-04-19

    -chemical environment and seepage water alteration by reaction with intruded basalt. The scope of this model only includes impacts to the components stated above, and does not include impacts to other engineered barrier system (EBS) components such as the waste package pallet. The results of this model report will be used in TSPA for several parameters including (1) temperature of magma (used for the temperature of the waste form after an intrusion) (2) temperature increase in Zone 2 due to intrusion to evaluate impact to Zone 2 waste packages; (3) effects of exsolved gases reaching Zone 2 to evaluate impact to Zone 2 waste packages; and (4) pH and ionic strength of water reacted with basalt to be used in conjunction with ''Dissolved Concentration Limits of Radioactive Elements'' (BSC 2003 [DIRS: 163152]) to determine solubility of spent fuel within the basalt. Ionic strength will also be used in conjunction with ''Waste Form and In-Drift Colloids-Associated Radionuclide Concentrations: Abstraction and Summary'' (BSC 2003 [DIRS: 166845]) for stability of colloids.

  8. Intrusion-Tolerant Architectures: Concepts and Design

    OpenAIRE

    Paulo Veríssimo; Nuno Ferreira Neves; Miguel Correia

    2003-01-01

    There is a significant body of research on distributed computing architectures, methodologies and algorithms, both in the fields of fault tolerance and security. Whilst they have taken separate paths until recently, the problems to be solved are of similar nature. In classical dependability, fault tolerance has been the workhorse of many solutions. Classical security-related work has on the other hand privileged, with few exceptions, intrusion prevention. Intrusion tolerance (IT) is a new app...

  9. Cluster based Intrusion Detection System for Manets

    Directory of Open Access Journals (Sweden)

    Nisha Dang

    2012-07-01

    Full Text Available Manets are the ad hoc networks that are build on demand or instantly when some mobile nodes come in the mobility range of each other and decide to cooperate for data transfer and communication. Therefore there is no defined topology for Manets. They communicate in dynamic topology which continuously changes as nodes are not stable. Due to this lack of infrastructure and distributed nature they are more vulnerable for attacks and provide a good scope to malicious users to become part of the network. To prevent the security of mobile ad hoc networks many security measures are designed such as encryption algorithms, firewalls etc. But still there is some scope of malicious actions. So, Intrusion detection systems are proposed to detect any intruder in the network and its malicious activities. Cluster based intrusion detection system is also designed to restrict the intruders activities in clusters of mobile nodes. In clusters each node run some intrusion detection code to detect local as well as global intrusion. In this paper we have taken insight of intrusion detection systems and different attacks on Manet security. Then we proposed how overhead involved in cluster based intrusion detection system can be reduced.

  10. A system for distributed intrusion detection

    Energy Technology Data Exchange (ETDEWEB)

    Snapp, S.R.; Brentano, J.; Dias, G.V.; Goan, T.L.; Heberlein, L.T.; Ho, Che-Lin; Levitt, K.N.; Mukherjee, B. (California Univ., Davis, CA (USA). Div. of Computer Science); Grance, T. (Air Force Cryptologic Support Center, San Antonio, TX (USA)); Mansur, D.L.; Pon, K.L. (Lawrence Livermore National Lab., CA (USA)); Smaha, S.E. (Haystack Labs., Inc., Austin, TX (USA))

    1991-01-01

    The study of providing security in computer networks is a rapidly growing area of interest because the network is the medium over which most attacks or intrusions on computer systems are launched. One approach to solving this problem is the intrusion-detection concept, whose basic premise is that not only abandoning the existing and huge infrastructure of possibly-insecure computer and network systems is impossible, but also replacing them by totally-secure systems may not be feasible or cost effective. Previous work on intrusion-detection systems were performed on stand-alone hosts and on a broadcast local area network (LAN) environment. The focus of our present research is to extend our network intrusion-detection concept from the LAN environment to arbitarily wider areas with the network topology being arbitrary as well. The generalized distributed environment is heterogeneous, i.e., the network nodes can be hosts or servers from different vendors, or some of them could be LAN managers, like our previous work, a network security monitor (NSM), as well. The proposed architecture for this distributed intrusion-detection system consists of the following components: a host manager in each host; a LAN manager for monitoring each LAN in the system; and a central manager which is placed at a single secure location and which receives reports from various host and LAN managers to process these reports, correlate them, and detect intrusions. 11 refs., 2 figs.

  11. Physical and numerical modeling of seawater intrusion in coastal aquifers

    Science.gov (United States)

    Crestani, Elena; Camporese, Matteo; Salandin, Paolo

    2016-04-01

    Seawater intrusion in coastal aquifers is a worldwide problem caused, among others factors, by aquifer overexploitation, rising sea levels, and climate changes. To limit the deterioration of both surface water and groundwater quality caused by saline intrusion, in recent years many research studies have been developed to identify possible countermeasures, mainly consisting of underground barriers. In this context, physical models are fundamental to study the saltwater intrusion, since they provide benchmarks for numerical model calibrations and for the evaluation of the effectiveness of general solutions to contain the salt wedge. This work presents a laboratory experiment where seawater intrusion was reproduced in a specifically designed sand-box. The physical model, built at the University of Padova, represents the terminal part of a coastal aquifer and consists of a flume 500 cm long, 30 cm wide and 60 cm high, filled for an height of 49 cm with glass beads characterized by a d50 of 0.6 mm and a uniformity coefficient d60/d10 ≈ 1.5. The resulting porous media is homogeneous, with porosity of about 0.37 and hydraulic conductivity of about 1.3×10-3 m/s. Upstream from the sand-box, a tank filled by freshwater provides the recharge to the aquifer. The downstream tank simulates the sea and red food dye is added to the saltwater to easily visualize the salt wedge. The volume of the downstream tank is about five times the upstream one, and, due to the small filtration discharge, salt concentration variations (i.e., water density variations) due to the incoming freshwater flow are negligible. The hydraulic gradient during the tests is constant, due to the fixed water level in the two tanks. Water levels and discharged flow rate are continuously monitored. The experiment presented here had a duration of 36 h. For the first 24 h, the saltwater wedge was let to evolve until quasi stationary condition was obtained. In the last 12 h, water withdrawal was carried out at a

  12. A Modeling Study on Saltwater Intrusion to Western Four Watercourses in the Pearl River Estuary

    Institute of Scientific and Technical Information of China (English)

    CHENG Xiang-ju; ZHAN Wei; GUO Zhen-ren; YUAN Li-rong

    2012-01-01

    Saltwater intrusion has been serious in the Pearl River estuary in recent years.For better understanding and analysis of the saltwater movement to the estuary,the three-dimensional Finite-Volume Coastal Ocean Model (FVCOM) is made to simulate the salinity intrusion to the four western watercourses in the Pearl River estuary under three semilunar conditions.With the measured and simulated Root Mean Square Error (RMSE) and the mean absolute percentage error of water level and salinity at multiple sites,the results show that the numerical water levels,salinity and flow velocities are in agreement with the measured data.It is acceptable and feasible to apply the FVCOM to simulate the salt water intrusion in the western four watercourses of the Pearl River.With the numerical data,the time and spatial movement patterns of saltwater intrusion along the Modao watercourse are analyzed.The salinity contour reaches its peak generally during 3~5 days before the spring tide.The salinity stratification is more obvious in the period of ebb tide than that in the rising tide whether in the spring or neap tides.Salt fluxes reflect changes of salt into the estuary,and the change rules are close to the rules of salinity intrusion.

  13. 磨刀门水道盐水强烈上溯规律和动力机制研究%Research of Law and Dynamic Mechanism for Strong Sa-line Water Intrusion in Modaomen Waterway

    Institute of Scientific and Technical Information of China (English)

    包芸; 刘杰斌; 任杰; 许炜铭; 戚志明

    2009-01-01

    通过流体力学场的概念做出磨刀门水道成界图,得到3个月长时间序列的盐水运动上溯距离和潮位的关系,从中发现总是在潮差最小的前后两天盐水上溯有一个突然增加的特点.从2005年初实测资料中整理分析发现,在整个珠江上游径流量较小时,由于分流比的变化,磨刀门水道在小潮期间有两天净泄量几乎为零,从而导致涨落潮的流动状态发生显著变异,涨潮历时为16 h,落潮历时仅为9 h.在此动力作用下盐水快速上溯,随后几天由于小潮期间潮汐动力作用不大,使得盐水滞留在磨刀门水道,直到大潮期间较强的潮汐动力作用将盐水带出,因而造成磨刀门水道异常的盐水上溯规律和严重的咸潮灾害.%Depend on the concept of fluid field, the salinity borderline figure of Modaomen waterway was made, and the relationship between saltwater movement distance and tidal elevation with three months long time series was gotten. The feature that the intrusion strength of saltwater always suddenly increased during the two days before and after time of the smallest tidal range was found. In the analysis of observed data in early 2005, net discharge amount of Modaomen waterway was found to be almost zero during neap tides because of the change of diversion ratio when the small Pearl River runoff, so that the flow state had notable variation that the flood duration had 16 hours and the ebb duration had only 9 hours. Affected by these dynamics, saltwater invaded rapidly. Later a few days during neap tides saltwater remained in Modaomen waterway due to the small tidal dynamic role, until spring tides saltwater was out of Modaomen waterway step by step due to the strong tidal dynamic role. Therefore, the abnormal law of saltwater intrusion was formed and the serious saline intrusion disaster was occurred in the Modaomen waterway.

  14. A New Method for Intrusion Detection using Manifold Learning Algorithm

    Directory of Open Access Journals (Sweden)

    Guoping Hou

    2013-07-01

    Full Text Available Computer and network security has received and will still receive much attention. Any unexpected intrusion will damage the network. It is therefore imperative to detect the network intrusion to ensure the normal operation of the internet. There are many studies in the intrusion detection and intrusion patter recognition. The artificial neural network (ANN has proven to be powerful for the intrusion detection. However, very little work has discussed the optimization of the input intrusion features for the ANN. Generally, the intrusion features contain a certain number of useless features, which is useless for the intrusion detection. Large dimensions of the feature data will also affect the intrusion detection performance of the ANN. In order to improve the ANN performance, a new approach for network intrusion detection based on nonlinear feature dimension reduction and ANN is proposed in this work. The manifold learning algorithm was used to reduce the intrusion feature vector. Then an ANN classifier was employed to identify the intrusion. The efficiency of the proposed method was evaluated with the real intrusion data. The test result shows that the proposed approach has good intrusion detection performance.

  15. Oxygen intrusion into anoxic fjords leads to increased methylmercury availability

    Science.gov (United States)

    Veiteberg Braaten, Hans Fredrik; Pakhomova, Svetlana; Yakushev, Evgeniy

    2013-04-01

    Mercury (Hg) appears in the oxic surface waters of the oceans at low levels (sub ng/L). Because inorganic Hg can be methylated into the toxic and bioaccumulative specie methylmercury (MeHg) levels can be high at the top of the marine food chain. Even though marine sea food is considered the main risk driver for MeHg exposure to people most research up to date has focused on Hg methylation processes in freshwater systems. This study identifies the mechanisms driving formation of MeHg during oxygen depletion in fjords, and shows how MeHg is made available in the surface water during oxygen intrusion. Studies of the biogeochemical structure in the water column of the Norwegian fjord Hunnbunn were performed in 2009, 2011 and 2012. In autumn of 2011 mixing flushing events were observed and lead to both positive and negative effects on the ecosystem state in the fjord. The oxygenated water intrusions lead to a decrease of the deep layer concentrations of hydrogen sulfide (H2S), ammonia and phosphate. On the other hand the intrusion also raised the H2S boundary from 8 m to a shallower depth of just 4 m. Following the intrusion was also observed an increase at shallower depths of nutrients combined with a decrease of pH. Before flushing events were observed concentrations of total Hg (TotHg) increased from 1.3 - 1.7 ng/L in the surface layer of the fjord to concentrations ranging from 5.2 ng/L to 6.4 ng/L in the anoxic zone. MeHg increased regularly from 0.04 ng/L in the surface water to a maximum concentration of 5.2 ng/L in the deeper layers. This corresponds to an amount of TotHg present as MeHg ranging from 2.1 % to 99 %. The higher concentrations of MeHg in the deeper layer corresponds to an area where no oxygen is present and concentrations of H2S exceeds 500 µM, suggesting a production of MeHg in the anoxic area as a result of sulphate reducing bacteria activity. After flushing the concentrations of TotHg showed a similar pattern ranging from 0.6 ng/L in the

  16. Data Mining and Intrusion Detection Systems

    Directory of Open Access Journals (Sweden)

    Zibusiso Dewa

    2016-01-01

    Full Text Available The rapid evolution of technology and the increased connectivity among its components, imposes new cyber-security challenges. To tackle this growing trend in computer attacks and respond threats, industry professionals and academics are joining forces in order to build Intrusion Detection Systems (IDS that combine high accuracy with low complexity and time efficiency. The present article gives an overview of existing Intrusion Detection Systems (IDS along with their main principles. Also this article argues whether data mining and its core feature which is knowledge discovery can help in creating Data mining based IDSs that can achieve higher accuracy to novel types of intrusion and demonstrate more robust behaviour compared to traditional IDSs.

  17. Intrusion Detection System: Security Monitoring System

    Directory of Open Access Journals (Sweden)

    ShabnamNoorani,

    2015-10-01

    Full Text Available An intrusion detection system (IDS is an ad hoc security solution to protect flawed computer systems. It works like a burglar alarm that goes off if someone tampers with or manages to get past other security mechanisms such as authentication mechanisms and firewalls. An Intrusion Detection System (IDS is a device or a software application that monitors network or system activities for malicious activities or policy violations and produces reports to a management station.Intrusion Detection System (IDS has been used as a vital instrument in defending the network from this malicious or abnormal activity..In this paper we are comparing host based and network based IDS and various types of attacks possible on IDS.

  18. An Adaptive Clustering Algorithm for Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    QIU Juli

    2007-01-01

    In this paper,we introduce an adaptive clustering algorithm for intrusion detection based on wavecluster which was introduced by Gholamhosein in 1999 and used with success in image processing.Because of the non-stationary characteristic of network traffic,we extend and develop an adaptive wavecluster algorithm for intrusion detection.Using the multiresolution property of wavelet transforms,we can effectively identify arbitrarily shaped clusters at different scales and degrees of detail,moreover,applying wavelet transform removes the noise from the original feature space and make more accurate cluster found.Experimental results on KDD-99 intrusion detection dataset show the efficiency and accuracy of this algorithm.A detection rate above 96% and a false alarm rate below 3% are achieved.

  19. An Overview on Intrusion Detection in Manet

    Directory of Open Access Journals (Sweden)

    Rajesh D. Wagh

    2015-05-01

    Full Text Available A mobile ad hoc network (MANET is a self-configuring of mobile devices network connected without wires and hence MANET has become a very popular technology now days. A MANETS are the networks that are building, when some mobile nodes come in the mobility range of each other for data transfer and communication. In MANET, nodes are not stable hence the communication topology is not stable due to this vulnerable for attacks. MANET devices are connected via wireless links without using an existing network infrastructure or centralized administration due to which MANETs are not able to diverse types of attacks and intrusions. Hence intrusion detection has attracted many researchers. This paper gives an overview and different methods to detect intrusion in MANET.

  20. Managing saltwater intrusion in coastal arid regions and its societal implications for agriculture

    Science.gov (United States)

    Grundmann, Jens; Al-Khatri, Ayisha; Schütze, Niels

    2016-05-01

    Coastal aquifers in arid and semiarid regions are particularly at risk due to intrusion of salty marine water. Since groundwater is predominantly used in irrigated agriculture, its excessive pumping - above the natural rate of replenishment - strengthen the intrusion process. Using this increasingly saline water for irrigation, leads to a destruction of valuable agricultural resources and the economic basis of farmers and their communities. The limitation of resources (water and soil) in these regions requires a societal adaptation and change in behaviour as well as the development of appropriate management strategies for a transition towards stable and sustainable future hydrosystem states. Besides a description of the system dynamics and the spatial consequences of adaptation on the resources availability, the contribution combines results of an empirical survey with stakeholders and physically based modelling of the groundwater-agriculture hydrosystem interactions. This includes an analysis of stakeholders' (farmers and decision makers) behaviour and opinions regarding several management interventions aiming on water demand and water resources management as well as the thinking of decision makers how farmers will behave. In this context, the technical counter measures to manage the saltwater intrusion by simulating different groundwater pumping strategies and scenarios are evaluated from the economic and social point of view and if the spatial variability of the aquifer's hydrogeology is taken into consideration. The study is exemplarily investigated for the south Batinah region in the Sultanate of Oman, which is affected by saltwater intrusion into a coastal aquifer system due to excessive groundwater withdrawal for irrigated agriculture.

  1. An overview to Software Architecture in Intrusion Detection System

    CERN Document Server

    Bahrami, Mehdi

    2012-01-01

    Network intrusion detection systems provide proactive defense against security threats by detecting and blocking attack-related traffic. This task can be highly complex, and therefore, software based network intrusion detection systems have difficulty in handling high speed links. This paper reviews of many type of software architecture in intrusion detection systems and describes the design and implementation of a high-performance network intrusion detection system that combines the use of software-based network intrusion detection sensors and a network processor board. The network processor acts as a customized load balancing splitter that cooperates with a set of modified content-based network intrusion detection sensors in processing network traffic.

  2. Effective analysis of cloud based intrusion detection system

    Directory of Open Access Journals (Sweden)

    Sanjay Ram

    2012-08-01

    Full Text Available The goal of IDS is to analyze events on the network and identify attacks. The increasing number of network security related incidents makes it necessary for organizations to actively protect their sensitive data with the installation of intrusion detection systems (IDS. People are paid more attention on intrusion detection which as an important computer network security technology. According to the development trend of intrusion detection, detecting all kinds of intrusions effectively requires a global view of the monitored network, Here, discuss about new intrusion detection mechanism based on cloud computing, which can make up for the deficiency of traditional intrusion detection, and proved to be great scalable.

  3. The history and evaluation of saltwater intrusion into a coastal aquifer in Mersin, Turkey.

    Science.gov (United States)

    Demirel, Zeynel

    2004-03-01

    The Mersin-Kazanli region is a densely industrialized region. The factories and towns cover their water demand from groundwater. With the increased water demand, saltwater intrusion has occurred. The chloride concentration of the water samples from some wells has been analysed periodically since these wells were drilled. The results of these analyses and electrical conductivity measurements were used to show the history and development of saltwater intrusion up to the year 2000. The Cl(-) concentration of the water within the alluvial aquifer increased to over 3000 mg/l in 1999 and the wells were closed completely. In 2001 new wells were drilled more than 1 km away from the sea and old well field. With the results of the analyses conducted in 2001, the current groundwater quality was determined. The ground water is of the magnesium-calcium-bicarbonate type and this composition is controlled by the interaction of the water with the sediments of alluvial deposits.

  4. Perceived illness intrusion among patients on hemodialysis

    Directory of Open Access Journals (Sweden)

    Bapat Usha

    2009-01-01

    Full Text Available Dialysis therapy is extremely stressful as it interferes with all spheres of daily acti-vities of the patients. This study is aimed at understanding the perceived illness intrusion among pa-tients on hemodialysis (HD and to find the association between illness intrusion and patient demo-graphics as well as duration of dialysis. A cross sectional study involving 90 patients with chronic kidney disease (CKD stage V, on HD was performed during the period from 2005 to 2006. The subjects included were above 18 years of age, willing, stable and on dialysis for at least two months. Patients with psychiatric co-morbidity were excluded. A semi-structured interview schedule covering socio-demographics and a 13 item illness intrusion checklist covering the various aspects of life was ca-rried out. The study patients were asked to rate the illness intrusion and the extent. The data were ana-lyzed statistically. The mean age of the subjects was 50.28 ± 13.69 years, males were predominant (85%, 73% were married, 50% belonged to Hindu religion, 25% had pre-degree education, 25% were employed and 22% were housewives. About 40% and 38% of the study patients belonged to middle and upper socio-economic strata respectively; 86% had urban background and lived in nuclear fami-lies. The mean duration on dialysis was 24 ± 29.6 months. All the subjects reported illness intrusion to a lesser or greater extent in various areas including: health (44%, work (70% finance (55%, diet (50% sexual life (38% and psychological status (25%. Illness had not intruded in areas of rela-tionship with spouse (67%, friends (76%, family (79%, social (40% and religious functions (72%. Statistically significant association was noted between illness intrusion and occupation (P= 0.02.

  5. Computationally Efficient Neural Network Intrusion Security Awareness

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Milos Manic

    2009-08-01

    An enhanced version of an algorithm to provide anomaly based intrusion detection alerts for cyber security state awareness is detailed. A unique aspect is the training of an error back-propagation neural network with intrusion detection rule features to provide a recognition basis. Network packet details are subsequently provided to the trained network to produce a classification. This leverages rule knowledge sets to produce classifications for anomaly based systems. Several test cases executed on ICMP protocol revealed a 60% identification rate of true positives. This rate matched the previous work, but 70% less memory was used and the run time was reduced to less than 1 second from 37 seconds.

  6. Adaptive Genetic Algorithm Model for Intrusion Detection

    Directory of Open Access Journals (Sweden)

    K. S. Anil Kumar

    2012-09-01

    Full Text Available Intrusion detection systems are intelligent systems designed to identify and prevent the misuse of computer networks and systems. Various approaches to Intrusion Detection are currently being used, but they are relatively ineffective. Thus the emerging network security systems need be part of the life system and this ispossible only by embedding knowledge into the network. The Adaptive Genetic Algorithm Model - IDS comprising of K-Means clustering Algorithm, Genetic Algorithm and Neural Network techniques. Thetechnique is tested using multitude of background knowledge sets in DARPA network traffic datasets.

  7. Intrusion Detection Using Cost-Sensitive Classification

    CERN Document Server

    Mitrokotsa, Aikaterini; Douligeris, Christos

    2008-01-01

    Intrusion Detection is an invaluable part of computer networks defense. An important consideration is the fact that raising false alarms carries a significantly lower cost than not detecting at- tacks. For this reason, we examine how cost-sensitive classification methods can be used in Intrusion Detection systems. The performance of the approach is evaluated under different experimental conditions, cost matrices and different classification models, in terms of expected cost, as well as detection and false alarm rates. We find that even under unfavourable conditions, cost-sensitive classification can improve performance significantly, if only slightly.

  8. Design of Secure Distributed Intrusion Detection Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Intrusion Detection System (IDS) have received a great deal of attention because of their excellent ability of preventing network incidents. Recently, many efficient approaches have been proposed to improve detection ability of IDS. While the self-protection ability of IDS is relatively worse and easy to be exploited by attackers, this paper gives a scheme of Securely Distributed Intrusion Detection System (SDIDS). This system adopts special measurements to enforce the security of IDS components. A new secure mechanism combining role-based access control and attribute certificate is used to resist attack to communication.

  9. Intrusion Detection Approach Using Connectionist Expert System

    Institute of Scientific and Technical Information of China (English)

    MA Rui; LIU Yu-shu; DU Yan-hui

    2005-01-01

    In order to improve the detection efficiency of rule-based expert systems, an intrusion detection approach using connectionist expert system is proposed. The approach converts the AND/OR nodes into the corresponding neurons, adopts the three-layered feed forward network with full interconnection between layers,translates the feature values into the continuous values belong to the interval [0, 1 ], shows the confidence degree about intrusion detection rules using the weight values of the neural networks and makes uncertain inference with sigmoid function. Compared with the rule-based expert system, the neural network expert system improves the inference efficiency.

  10. Intrusion Detection amp Prevention Systems - Sourcefire Snort

    Directory of Open Access Journals (Sweden)

    Rajesh Vuppala

    2015-08-01

    Full Text Available Information security is a challenging issue for all business organizations today amidst increasing cyber threats. While there are many alternative intrusion detection amp prevention systems available to choose from selecting the best solution to implement to detect amp prevent cyber-attacks is a difficult task. The best solution is of the one that gets the best reviews and suits the organizations needs amp budget. In this review paper we summarize various classes of intrusion detection and prevention systems compare features of alternative solutions and make recommendation for implementation of one as the best solution for business organization in Fiji.

  11. Computationally Efficient Neural Network Intrusion Security Awareness

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Milos Manic

    2009-08-01

    An enhanced version of an algorithm to provide anomaly based intrusion detection alerts for cyber security state awareness is detailed. A unique aspect is the training of an error back-propagation neural network with intrusion detection rule features to provide a recognition basis. Network packet details are subsequently provided to the trained network to produce a classification. This leverages rule knowledge sets to produce classifications for anomaly based systems. Several test cases executed on ICMP protocol revealed a 60% identification rate of true positives. This rate matched the previous work, but 70% less memory was used and the run time was reduced to less than 1 second from 37 seconds.

  12. THREE-DIMENSIONAL NUMERICAL STUDY FOR SALT WATER INTRUSION IN MULTI-LAYERED COASTAL AQUIFERS IN THE JAHE RIVER BASIN,SHANDONG PROVINCE,CHINA%山东烟台夹河中、下游地区海水入侵 三维水质数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    成建梅; 陈崇希; 吉孟瑞; 孙桂明

    2001-01-01

    A three-dimensional variable density flow and transport model hasbeen developed to study the salt water intrusion in the Jahe River Basin, Shandong Province, China. Based on tetrahedral element, the authors derived the numerical approximation procedure of 3D density-dependent saltwater intrusion model. The density-dependent flow equation is solved numerically by Galerkin FEM formation. The solute transport equation is solved by means of a coupled Eulerian-Lagrangian method in which advection part is separated to dispersion part and calculated by a hybrid method of characteristics so as to improve the precision of concentration solution of advective part. In using of density-dependent tidal effect model, the equivalent boundary toward sea in confined aquifer is determined according to tidal fluctuation information. The aquifer parameters in the Jahe River Basin are estimated by converging long-term observation data of hydraulic head and chloride concentration. Through numerical analysis and prediction, it is concluded that the main reason for saltwater intrusion is excessive groundwater exploitation and improper arrangement of pump wells in the lower reaches of the Jahe River Basin. Besides, seawater comes into river because of tidal effect. Therefore, groundwater near river is contaminated by saltwater in tongue form. By predicting the tendency of water saline quality under several conditions, two measures are suggested to prevent salt water intrusion.%建立了三维变密度对流弥散水质数学模型来研究山东省烟台夹河中、下游地区咸淡水界面的运移规律。以四面体为基本离散单元,推导出三维海水入侵变密度水质模型求解的数值方法,其中水流方程求解时运用了迦辽金有限单元法。溶质运移方程求解时运用了欧拉拉格朗日混合方法,将对流项与弥散项分离,用传统迦辽金有限元方法求解弥散项;采用自适应MOC-MMOC法求解对流项,以消除人工过

  13. Two Issues in Premise Plumbing: Contamination Intrusion at Service Line and Choosing Alternative Plumbing Material

    OpenAIRE

    Lee, Juneseok

    2008-01-01

    Worldwide water distribution infrastructure system is old and deteriorating. A water system with its myriad appurtenances (including pumps and valves and tanks) is susceptible to hydraulic transients resulting in high and low pressure waves alternatively passing through the network. While both low and high pressure events structurally tax the already weak system, there is copious evidence indicating intrusion of contaminants into the drinking water pipes from the pipeâ s exterior environment...

  14. Numerical simulation of the Kuroshio intrusion into the South China Sea by a passive tracer

    Institute of Scientific and Technical Information of China (English)

    LIU Tongya; XU Jiexin; HE Yinghui; L Haibin; YAO Yuan; CAI Shuqun

    2016-01-01

    Owing to lack of observational data and accurate definition, it is difficult to distinguish the Kuroshio intrusion water from the Pacific Ocean into the South China Sea (SCS). By using a passive tracer to identify the Kuroshio water based on an observation-validated three-dimensional numerical model MITgcm, the spatio-temporal variation of the Kuroshio intrusion water into the SCS has been investigated. Our result shows the Kuroshio intrusion is of distinct seasonal variation in both horizontal and vertical directions. In winter, the intruding Kuroshio water reaches the farthest, almost occupying the area from 18°N to 23°N and 114°E to 121°E, with a small branch flowing towards the Taiwan Strait. The intrusion region of the Kuroshio water decreases with depth gradually. However, in summer, the Kuroshio water is confined to the east of 118°E without any branch reaching the Taiwan Strait; meanwhile the intrusion region of the Kuroshio water increases from the surface to the depth about 205 m, then it decreases with depth. The estimated annual mean of Kuroshio Intrusion Transport (KIT) via the Luzon Strait is westward to the SCS in an amount of –3.86×106 m3/s, which is larger than the annual mean of Luzon Strait Transport (LST) of –3.15×106 m3/s. The KIT above 250 m accounts for 60%–80% of the LST throughout the entire water column. By analyzing interannual variation of the Kuroshio intrusion from the year 2003 to 2012, we find that the Kuroshio branch flowing into the Taiwan Strait is the weaker in winter of La Niña years than those in El Niño and normal years, which may be attributed to the wind stress curl off the southeast China then. Furthermore, the KIT correlates the Niño 3.4 index from 2003 to 2012 with a correlation coefficient of 0.41, which is lower than that of the LST with the Niño 3.4 index, i.e., 0.78.

  15. Intrusion Detection in SCADA Networks

    NARCIS (Netherlands)

    Barbosa, Rafael Ramos Regis; Pras, Aiko; Stiller, Burckhard; De Turck, Filip

    2010-01-01

    Supervisory Control and Data Acquisition (SCADA) sys- tems are a critical part of large industrial facilities, such as water dis- tribution infrastructures. With the goal of reducing costs and increas- ing efficiency, these systems are becoming increasingly interconnected. However, this has also exp

  16. Data Mining Approaches for Intrusion Detection

    Science.gov (United States)

    2007-11-02

    In this paper we discuss our research in developing general and systematic methods for intrusion detection. The key ideas are to use data mining techniques...two general data mining algorithms that we have implemented: the association rules algorithm and the frequent episodes algorithm. These algorithms can

  17. Intrusion Detection System Visualization of Network Alerts

    Science.gov (United States)

    2010-07-01

    Intrusion Detection System Visualization of Network Alerts Dolores M. Zage and Wayne M. Zage Ball State University Final Report July 2010...contracts. Staff Wayne Zage, Director of the S2ERC and Professor, Department of Computer Science, Ball State University Dolores Zage, Research

  18. Chemical Observations of a Polar Vortex Intrusion

    Science.gov (United States)

    Schoeberl, M. R.; Kawa, S. R.; Douglass, A. R.; McGee, T. J.; Browell, E.; Waters, J.; Livesey, N.; Read, W.; Froidevaux, L.

    2006-01-01

    An intrusion of vortex edge air in D the interior of the Arctic polar vortex was observed on the January 31,2005 flight of the NASA DC-8 aircraft. This intrusion was identified as anomalously high values of ozone by the AROTAL and DIAL lidars. Our analysis shows that this intrusion formed when a blocking feature near Iceland collapsed, allowing edge air to sweep into the vortex interior. along the DC-8 flight track also shows the intrusion in both ozone and HNO3. Polar Stratospheric Clouds (PSCs) were observed by the DIAL lidar on the DC-8. The spatial variability of the PSCs can be explained using MLS HNO3 and H2O observations and meteorological analysis temperatures. We also estimate vortex denitrification using the relationship between N2O and HNO3. Reverse domain fill back trajectory calculations are used to focus on the features in the MLS data. The trajectory results improve the agreement between lidar measured ozone and MLS ozone and also improve the agreement between the HNO3 measurements PSC locations. The back trajectory calculations allow us to compute the local denitrification rate and reduction of HCl within the filament. We estimate a denitrification rate of about lO%/day after exposure to below PSC formation temperature. Analysis of Aura MLS observations made

  19. Root resorption after orthodontic intrusion and extrusion:.

    NARCIS (Netherlands)

    Han, G.; Huang, S.; Hoff, J.W. Von den; Zeng, X.; Kuijpers-Jagtman, A.M.

    2005-01-01

    The aim of this investigation was to compare root resorption in the same individual after application of continuous intrusive and extrusive forces. In nine patients (mean age 15.3 years), the maxillary first premolars were randomly intruded or extruded with a continuous force of 100 cN for eight wee

  20. Access Control from an Intrusion Detection Perspective

    NARCIS (Netherlands)

    Nunes Leal Franqueira, V.

    Access control and intrusion detection are essential components for securing an organization's information assets. In practice, these components are used in isolation, while their fusion would contribute to increase the range and accuracy of both. One approach to accomplish this fusion is the

  1. Relationship between vapor intrusion and human exposure to trichloroethylene.

    Science.gov (United States)

    Archer, Natalie P; Bradford, Carrie M; Villanacci, John F; Crain, Neil E; Corsi, Richard L; Chambers, David M; Burk, Tonia; Blount, Benjamin C

    2015-01-01

    Trichloroethylene (TCE) in groundwater has the potential to volatilize through soil into indoor air where it can be inhaled. The purpose of this study was to determine whether individuals living above TCE-contaminated groundwater are exposed to TCE through vapor intrusion. We examined associations between TCE concentrations in various environmental media and TCE concentrations in residents. For this assessment, indoor air, outdoor air, soil gas, and tap water samples were collected in and around 36 randomly selected homes; blood samples were collected from 63 residents of these homes. Additionally, a completed exposure survey was collected from each participant. Environmental and blood samples were analyzed for TCE. Mixed model multiple linear regression analyses were performed to determine associations between TCE in residents' blood and TCE in indoor air, outdoor air, and soil gas. Blood TCE concentrations were above the limit of quantitation (LOQ; ≥ 0.012 µg L(-1)) in 17.5% of the blood samples. Of the 36 homes, 54.3%, 47.2%, and >84% had detectable concentrations of TCE in indoor air, outdoor air, and soil gas, respectively. Both indoor air and soil gas concentrations were statistically significantly positively associated with participants' blood concentrations (P = 0.0002 and P = 0.04, respectively). Geometric mean blood concentrations of residents from homes with indoor air concentrations of >1.6 µg m(-3) were approximately 50 times higher than geometric mean blood TCE concentrations in participants from homes with no detectable TCE in indoor air (P < .0001; 95% CI 10.4-236.4). This study confirms the occurrence of vapor intrusion and demonstrates the magnitude of exposure from vapor intrusion of TCE in a residential setting.

  2. NADIR (Network Anomaly Detection and Intrusion Reporter): A prototype network intrusion detection system

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, K.A.; DuBois, D.H.; Stallings, C.A.

    1990-01-01

    The Network Anomaly Detection and Intrusion Reporter (NADIR) is an expert system which is intended to provide real-time security auditing for intrusion and misuse detection at Los Alamos National Laboratory's Integrated Computing Network (ICN). It is based on three basic assumptions: that statistical analysis of computer system and user activities may be used to characterize normal system and user behavior, and that given the resulting statistical profiles, behavior which deviates beyond certain bounds can be detected, that expert system techniques can be applied to security auditing and intrusion detection, and that successful intrusion detection may take place while monitoring a limited set of network activities such as user authentication and access control, file movement and storage, and job scheduling. NADIR has been developed to employ these basic concepts while monitoring the audited activities of more than 8000 ICN users.

  3. Simulation of network intrusion detection system with GPenSim

    OpenAIRE

    2011-01-01

    In recent years, network has penetrated into every aspect of our life with its rapid growth and popularization. More and more serious network security problems have occurred together with this process, especially network intrusion problem. It has seriously affected the normal use of network, so research of network intrusion detection has become one of the hottest research areas. This thesis simulated a network intrusion detection system based on particle filter to solve the network intrusion ...

  4. Towards Multi-Stage Intrusion Detection using IP Flow Records

    OpenAIRE

    Muhammad Fahad Umer; Muhammad Sher; Imran Khan

    2016-01-01

    Traditional network-based intrusion detection sys-tems using deep packet inspection are not feasible for modern high-speed networks due to slow processing and inability to read encrypted packet content. As an alternative to packet-based intrusion detection, researchers have focused on flow-based intrusion detection techniques. Flow-based intrusion detection systems analyze IP flow records for attack detection. IP flow records contain summarized traffic information. However, flow data is very ...

  5. Efficiency of Svm and Pca to Enhance Intrusion Detection System

    OpenAIRE

    Soukaena Hassan Hashem

    2013-01-01

    Intrusion detection system (IDS) is a system that gathers and analyzes information from various areas within a computer or a network to identify attacks made against these components. This research proposed an Intrusion Detection Model (IDM) for detection intrusion attempts, the proposal is a hybrid IDM because it considers both features of network packets and host features that are sensitive to most intrusions. The dataset used to build the hybrid IDM is the proposed HybD (Hybrid Dataset) da...

  6. EFFECT OF SALT WEDGE INTRUSION IN KUSHIRO WETLAND CONSIDERING SEA LEVEL RISE

    Science.gov (United States)

    Nakamoto, Atsushi; Shintani, Tetsuya; Nakayama, Keisuke; Maruya, Yasuyuki; Ishida, Tetsuya; Houmura, Kenichi

    This paper describes the effect of sea-level rise (SLR) on the salt wedge intrusion in terms of ecological system in Kushiro wetland. Kushiro wetland was registered by Ramsar Treaty and the largest wetland in Japan. A previous study demonstrates that the salt wedge intrusion may not affect ecological system of Kushiro wetland, such as loss of freshwater plants along Kushiro River. However, it is revealed that SLR may occur in the end of the 21st century, which enhances the increase in the distance of the salt wedge intrusion along Kushiro River and the loss of endangered species of Kushiro wetland along Kushiro River. This study thus aims to investigate the influence of the salt wedge intrusion on freshwater plants along Kushiro River, and to clarify the salt wedge intrusion when SLR occurs due to climate change. We attempted to investigate the influence of SLR on endangered species along Kyu-Kushiro River in which sea water is likely to intrude up to about 8 km from the river mouth. As results, it is suggested from field observations that salinity may decrease freshwater plants along Kushiro River, and it clarifies the possibility that the salt wedge intrudes Kushiro River due to SLR by using 3D hydrodynamic model, Fantom3D.

  7. Impact of seasonal tide variation on saltwater intrusion in the Changjiang River estuary

    Institute of Scientific and Technical Information of China (English)

    QIU Cheng; ZHU Jianrong; GU Yuliang

    2012-01-01

    An improved 3-D ECOM-si model was used to study the impact of seasonal tide variation on saltwater intrusion into the Changjiang River estuary,especially at the bifurcation of the North Branch (NB) and the South Branch (SB).The study assumes that the river discharge and wind are constant.The model successfully reproduced the saltwater intrusion.During spring tide,there is water and salt spillover (WSO and SSO) from the NB into the SB,and tidally averaged (net) water and salt fluxes are 985 m3/s and 24.8 ton/s,respectively.During neap tide,the WSO disappears and its net water flux is 122 m3/s.Meanwhile,the SSO continues,with net salt flux of 1.01 ton/s,much smaller than during spring tide.Because the tidal range during spring tide is smaller in June than in March,overall saltwater intrusion is weaker in June than in March during that tidal period.However,the WSO and SSO still exist in June.Net water and salt fluxes in that month are 622 m3/s and 15.35 ton/s,respectively,decreasing by 363 m3/s and 9.45 ton/s over those in March.Because tidal range during neap tide is greater in June than in March,saltwater intrusion in June is stronger than in March during that tidal period.The WSO and SSO appear in June,with net water and salt fluxes of 280 m3/s and 8.55 ton/s,respectively,increasing by 402 m3/s and 7.54 ton/s over those in March.Saltwater intrusion in the estuary is controlled by the river discharge,semi-diurnal flood-ebb tide,semi-monthly spring or neap tide,and seasonal tide variation.

  8. Conjunctive Management of Multi-Aquifer System for Saltwater Intrusion Mitigation

    Science.gov (United States)

    Tsai, F. T. C.; Pham, H. V.

    2015-12-01

    Due to excessive groundwater withdrawals, many water wells in Baton Rouge, Louisiana experience undesirable chloride concentration because of saltwater intrusion. The study goal is to develop a conjunctive management framework that takes advantage of the Baton Rouge multi-aquifer system to mitigate saltwater intrusion. The conjunctive management framework utilizes several hydraulic control techniques to mitigate saltwater encroachment. These hydraulic control approaches include pumping well relocation, freshwater injection, saltwater scavenging, and their combinations. Specific objectives of the study are: (1) constructing scientific geologic architectures of the "800-foot" sand, the "1,000-foot" sand, the "1,200-foot" sand, the "1,500-foot" sand, the "1,700-foot" sand, and the "2,000-foot" sand, (2) developing scientific saltwater intrusion models for these sands. (3) using connector wells to draw native groundwater from one sand and inject to another sand to create hydraulic barriers to halt saltwater intrusion, (4) using scavenger wells or well couples to impede saltwater intrusion progress and reduce chloride concentration in pumping wells, and (5) reducing cones of depression by relocating and dispersing pumping wells to different sands. The study utilizes optimization techniques and newest LSU high performance computing (HPC) facilities to derive solutions. The conjunctive management framework serves as a scientific tool to assist policy makers to solve the urgent saltwater encroachment issue in the Baton Rouge area. The research results will help water companies as well as industries in East Baton Rouge Parish and neighboring parishes by reducing their saltwater intrusion threats, which in turn would sustain Capital Area economic development.

  9. Liquidus temperatures for the layered series of the Skaergaard intrusion

    Science.gov (United States)

    Thy, P.; Tegner, C.; Lesher, C. E.

    2009-12-01

    empirical linear relationship (T oC = 899 + 3.6 An; 1σ = 20 oC). This relationship predicts a total crystallization interval for the intrusion of ~150 oC. Plagioclase crystallized in the Hidden Zone (An71) at 1155 oC, at the base of the Lower Zone (An66) at 1137 oC, and finally in the Sandwich Horizon (An30) at 1007 oC. These temperatures are in good agreements with previous estimates based on melting studies of suitable chilled margin rocks and gabbros from the Skaergaard intrusion and liquid line of descent modeling. Proposed variations in magmatic pressure during Skaergaard evolution and reasonable estimates of magmatic water contents do not alter these conclusions.

  10. The state of the art in intrusion prevention and detection

    CERN Document Server

    Pathan, Al-Sakib Khan

    2013-01-01

    The State of the Art in Intrusion Prevention and Detection analyzes the latest trends and issues surrounding intrusion detection systems in computer networks, especially in communications networks. Its broad scope of coverage includes wired, wireless, and mobile networks; next-generation converged networks; and intrusion in social networks.Presenting cutting-edge research, the book presents novel schemes for intrusion detection and prevention. It discusses tracing back mobile attackers, secure routing with intrusion prevention, anomaly detection, and AI-based techniques. It also includes infor

  11. Research on IPv6 intrusion detection system Snort-based

    Science.gov (United States)

    Shen, Zihao; Wang, Hui

    2010-07-01

    This paper introduces the common intrusion detection technologies, discusses the work flow of Snort intrusion detection system, and analyzes IPv6 data packet encapsulation and protocol decoding technology. We propose the expanding Snort architecture to support IPv6 intrusion detection in accordance with CIDF standard combined with protocol analysis technology and pattern matching technology, and present its composition. The research indicates that the expanding Snort system can effectively detect various intrusion attacks; it is high in detection efficiency and detection accuracy and reduces false alarm and omission report, which effectively solves the problem of IPv6 intrusion detection.

  12. ISDTM:An Intrusion Signatures Description Temporal Model

    Institute of Scientific and Technical Information of China (English)

    OuYangMing-guang; ZhouYang-bo

    2003-01-01

    ISDTM, based on an augmented Allen's interval temporal logic (ITL) and first-order predicate calculus, is a formal temporal model for representing intrusion signatures.It is augmented with some real time extensions which enhance the expressivity. Intrusion scenarios usually are the set of events and system states, wherethe temporal sequence is their basic relation. Intrusion signatures description, therefore, is to represent such temporal relations in a sense. While representing these signatures, ISDTM decomposes the intrusion process into the sequence of events according to their relevant intervals, and then specifies network states in these Intervals. The uncertain intrusion signatures as well as basic temporal modes of events, which consist of the parallel mode,the sequential mode and the hybrid mode, can be succinctly and naturally represented in ISDTM. Mode chart is the visualization of intrusion signatures in ISDTM, which makes the formulas more readable. The intrusion signatures descriptions in ISDTM have advantages of compact construct, concise syntax, scalability and easy implementation.

  13. A Comprehensive Study in Data Mining Frameworks for Intrusion Detection

    Directory of Open Access Journals (Sweden)

    R.Venkatesan

    2012-12-01

    Full Text Available Intrusions are the activities that violate the security policy of system. Intrusion Detection is the process used to identify intrusions. Network security is to be considered as a major issue in recent years, since the computer network keeps on expanding every day. An Intrusion Detection System (IDS is a system for detecting intrusions and reporting to the authority or to the network administration. Data mining techniques have been successfully applied in many fields like Network Management, Education, Science, Business, Manufacturing, Process control, and Fraud Detection. Data Mining for IDS is the technique which can be used mainly to identify unknown attacks and to raise alarms when security violations are detected. The purpose of this survey paper is to describe the methods/ techniques which are being used for Intrusion Detection based on Data mining concepts and the designed frame works for the same. We are also going to review the related works for intrusion detection.

  14. Using Jquery with Snort to Visualize Intrusion

    Directory of Open Access Journals (Sweden)

    Alaa El - Din Riad

    2012-01-01

    Full Text Available The explosive growth of malicious activities on worldwide communication networks, such as the Internet, has highlighted the need for efficient intrusion detection systems. The efficiency of traditional intrusion detection systems is limited by their inability to effectively relay relevant information due to their lack of interactive / immersive technologies. Visualized information is a technique that can encode large amounts of complex interrelated data, being at the same time easily quantified, manipulated, and processed by a human user. Authors have found that the representations can be quite effective at conveying the needed information and resolving the relationships extremely rapidly. To facilitate the creation of novel visualizations this paper presents a new framework that is designed with using data visualization technique by using Jquery Php for analysis and visualizes snort result data for user.

  15. Iron isotope systematics of the Skaergaard intrusion

    DEFF Research Database (Denmark)

    Lesher, Charles; Lundstrom, C.C.; Barfod, Gry

    report the results of a broad study of the iron isotope compositions of gabbros within the layered and upper border series of the Skaergaard intrusion, pegmatite and granophyre associated with these gabbroic rocks, and the sandwich horizon thought to represent the product of extreme differentiation and/or...... crystallization on non-traditional stable isotope systems, particularly iron. FeTi oxide minerals (titanomagnetite and ilmenite) appear after ~60% of the magma had solidified. This was a significant event affecting the liquid line of descent and potentially accompanied by iron isotope fractionation. Here we...... liquid immiscibility. Forty-eight whole rock samples from well-constrained stratigraphic levels in the intrusion were crushed, powdered and dissolved, followed by iron separation by ion chromatography. Purified solutions were analyzed by MC- ICPMS in high-resolution mode using the sample-std bracket...

  16. In-situ trainable intrusion detection system

    Energy Technology Data Exchange (ETDEWEB)

    Symons, Christopher T.; Beaver, Justin M.; Gillen, Rob; Potok, Thomas E.

    2016-11-15

    A computer implemented method detects intrusions using a computer by analyzing network traffic. The method includes a semi-supervised learning module connected to a network node. The learning module uses labeled and unlabeled data to train a semi-supervised machine learning sensor. The method records events that include a feature set made up of unauthorized intrusions and benign computer requests. The method identifies at least some of the benign computer requests that occur during the recording of the events while treating the remainder of the data as unlabeled. The method trains the semi-supervised learning module at the network node in-situ, such that the semi-supervised learning modules may identify malicious traffic without relying on specific rules, signatures, or anomaly detection.

  17. An immune based dynamic intrusion detection model

    Institute of Scientific and Technical Information of China (English)

    LI Tao

    2005-01-01

    With the dynamic description method for self and antigen, and the concept of dynamic immune tolerance for lymphocytes in network-security domain presented in this paper, a new immune based dynamic intrusion detection model (Idid) is proposed. In Idid, the dynamic models and the corresponding recursive equations of the lifecycle of mature lymphocytes, and the immune memory are built. Therefore, the problem of the dynamic description of self and nonself in computer immune systems is solved, and the defect of the low efficiency of mature lymphocyte generating in traditional computer immune systems is overcome. Simulations of this model are performed, and the comparison experiment results show that the proposed dynamic intrusion detection model has a better adaptability than the traditional methods.

  18. Iron isotope systematics of the Skaergaard intrusion

    DEFF Research Database (Denmark)

    Lesher, Charles; Lundstrom, C.C.; Barfod, Gry

    crystallization on non-traditional stable isotope systems, particularly iron. FeTi oxide minerals (titanomagnetite and ilmenite) appear after ~60% of the magma had solidified. This was a significant event affecting the liquid line of descent and potentially accompanied by iron isotope fractionation. Here we...... report the results of a broad study of the iron isotope compositions of gabbros within the layered and upper border series of the Skaergaard intrusion, pegmatite and granophyre associated with these gabbroic rocks, and the sandwich horizon thought to represent the product of extreme differentiation and....../or liquid immiscibility. Forty-eight whole rock samples from well-constrained stratigraphic levels in the intrusion were crushed, powdered and dissolved, followed by iron separation by ion chromatography. Purified solutions were analyzed by MC- ICPMS in high-resolution mode using the sample-std bracket...

  19. A Survey on Intrusion Detection in MANETs.

    Science.gov (United States)

    BakeyaLakshmi, P.; Santhi, K.

    2012-10-01

    A mobile ad hoc network is an infrastructureless network that changes its links dynamically, which makes routing in MANET a difficult process. As Mobile Ad-Hoc Network (MANET) has become a very important technology, research concerning its security problem, especially, in intrusion detection has attracted many researchers. Feature selection methodology plays a vital role in the data analysis process. PCA is used to analyze the selected features. This is because, redundant and irrelevant features often reduce performance of the intrusion detection system. It performs better in increasing speed and predictive accuracy. This survey aims to select and analyze the network features using principal component analysis. While performing various experiments, normal and attack states are simulated and the results for the selected features are analyzed.

  20. Intrusion Detection in Wireless Body Sensor Networks

    Directory of Open Access Journals (Sweden)

    Nadya El MOUSSAID

    2017-01-01

    Full Text Available The recent advances in electronic and robotics industry have enabled the manufacturing of sensors capable of measuring a set of application-oriented parameters and transmit them back to the base station for analysis purposes. These sensors are widely used in many applications including the healthcare systems forming though a Wireless Body Sensor Networks. The medical data must be highly secured and possible intrusion has to be fully detected to proceed with the prevention phase. In this paper, we propose a new intrusion superframe schema for 802.15.6 standard to detect the cloning attack. The results proved the efficiency of our technique in detecting this type of attack based on 802.15.6 parameters performances coupled with frequency switching at the radio model.

  1. Sensing Danger: Innate Immunology for Intrusion Detection

    CERN Document Server

    Uwe, Aickelin

    2008-01-01

    The immune system provides an ideal metaphor for anomaly detection in general and computer security in particular. Based on this idea, artificial immune systems have been used for a number of years for intrusion detection, unfortunately so far with little success. However, these previous systems were largely based on immunological theory from the 1970s and 1980s and over the last decade our understanding of immunological processes has vastly improved. In this paper we present two new immune inspired algorithms based on the latest immunological discoveries, such as the behaviour of Dendritic Cells. The resultant algorithms are applied to real world intrusion problems and show encouraging results. Overall, we believe there is a bright future for these next generation artificial immune algorithms.

  2. A Survey on VANET Intrusion Detection Systems

    Directory of Open Access Journals (Sweden)

    Mohammed ERRITALI

    2013-04-01

    Full Text Available In recent years, the security issues on Vehicular ad hoc networks (VANETs have become one of the primary concerns. The VANET is inherently very vulnerable to attacks than wired network because it is characterized by high mobility, shared wireless medium and the absence of centralized security services offered by dedicated equipment such as firewalls and authentication servers. Attackcountermeasures such as digital signature and encryption, can be used as the first line of defense for reducing the possibilities of attacks. However, these techniques have limited prevention in general, and they are designed for a set of known attacks. They are unlikely to avoid most recent attacks that are designed to circumvent existing security measures. For this reason, there is a need of second technique to “detect and notify” these newer attacks, i.e. “intrusion detection”. This article aims to present and classifycurrent techniques of Intrusion Detection System (IDS aware VANETs.

  3. Multilayer Statistical Intrusion Detection in Wireless Networks

    Directory of Open Access Journals (Sweden)

    Noureddine Boudriga

    2008-12-01

    Full Text Available The rapid proliferation of mobile applications and services has introduced new vulnerabilities that do not exist in fixed wired networks. Traditional security mechanisms, such as access control and encryption, turn out to be inefficient in modern wireless networks. Given the shortcomings of the protection mechanisms, an important research focuses in intrusion detection systems (IDSs. This paper proposes a multilayer statistical intrusion detection framework for wireless networks. The architecture is adequate to wireless networks because the underlying detection models rely on radio parameters and traffic models. Accurate correlation between radio and traffic anomalies allows enhancing the efficiency of the IDS. A radio signal fingerprinting technique based on the maximal overlap discrete wavelet transform (MODWT is developed. Moreover, a geometric clustering algorithm is presented. Depending on the characteristics of the fingerprinting technique, the clustering algorithm permits to control the false positive and false negative rates. Finally, simulation experiments have been carried out to validate the proposed IDS.

  4. A Review of Vapor Intrusion Models

    OpenAIRE

    Yao, Yijun; Suuberg, Eric M.

    2013-01-01

    A complete vapor intrusion (VI) model, describing vapor entry of volatile organic chemicals (VOCs) into buildings located on contaminated sites, generally consists of two main parts-one describing vapor transport in the soil and the other its entry into the building. Modeling the soil vapor transport part involves either analytically or numerically solving the equations of vapor advection and diffusion in the subsurface. Contaminant biodegradation must often also be included in this simulatio...

  5. Artificial Intrusion Detection Techniques: A Survey

    Directory of Open Access Journals (Sweden)

    Ashutosh Gupta

    2014-08-01

    Full Text Available Networking has become the most integral part of our cyber society. Everyone wants to connect themselves with each other. With the advancement of network technology, we find this most vulnerable to breach and take information and once information reaches to the wrong hands it can do terrible things. During recent years, number of attacks on networks have been increased which drew the attention of many researchers on this field. There have been many researches on intrusion detection lately. Many methods have been devised which are really very useful but they can only detect the attacks which already took place. These methods will always fail whenever there is a foreign attack which is not famous or which is new to the networking world. In order to detect new intrusions in the network, researchers have devised artificial intelligence technique for Intrusion detection prevention system. In this paper we are going to cover what types evolutionary techniques have been devised and their significance and modification.

  6. A BOOSTING APPROACH FOR INTRUSION DETECTION

    Institute of Scientific and Technical Information of China (English)

    Zan Xin; Han Jiuqiang; Zhang Junjie; Zheng Qinghua; Han Chongzhao

    2007-01-01

    Intrusion detection can be essentially regarded as a classification problem,namely,distinguishing normal profiles from intrusive behaviors.This paper introduces boosting classification algorithm into the area of intrusion detection to learn attack signatures.Decision tree algorithm is used as simple base learner of boosting algorithm.Furthermore,this paper employs the Principle Component Analysis(PCA)approach,an effective data reduction approach,to extract the key attribute set from the original high-dimensional network traffic data.KDD CUP 99 data set is used in these exDeriments to demonstrate that boosting algorithm can greatly improve the clas.sification accuracy of weak learners by combining a number of simple"weak learners".In our experiments,the error rate of training phase of boosting algorithm is reduced from 30.2%to 8%after 10 iterations.Besides,this Daper also compares boosting algorithm with Support Vector Machine(SVM)algorithm and shows that the classification accuracy of boosting algorithm is little better than SVM algorithm's.However,the generalization ability of SVM algorithm is better than boosting algorithm.

  7. Intrusion Detection with Multi-Connected Representation

    Directory of Open Access Journals (Sweden)

    Abdelkader Khobzaoui

    2016-01-01

    Full Text Available Recently, considerable attention has been given to data mining techniques to improve the performance of intrusion detection systems (IDS. This has led to the application of various classification and clustering techniques for the purpose of intrusion detection. Most of them assume that behaviors, both normal and intrusions, are represented implicitly by connected classes. We state that such assumption isn't evident and is a source of the low detection rate and false alarm. This paper proposes a suitable method able to reach high detection rate and overcomes the disadvantages of conventional approaches which consider that behaviors must be closed to connected representation only. The main strategy of the proposed method is to segment sufficiently each behavior representation by connected subsets called natural classes which are used, with a suitable metric, as tools to build the expected classifier. The results show that the proposed model has many qualities compared to conventional models; especially regarding those have used DARPA data set for testing the effectiveness of their methods. The proposed model provides decreased rates both for false negative rates and for false positives.

  8. Intrusion detection using rough set classification

    Institute of Scientific and Technical Information of China (English)

    张连华; 张冠华; 郁郎; 张洁; 白英彩

    2004-01-01

    Recently machine learning-based intrusion detection approaches have been subjected to extensive researches because they can detect both misuse and anomaly. In this paper, rough set classification (RSC), a modern learning algorithm, is used to rank the features extracted for detecting intrusions and generate intrusion detection models. Feature ranking is a very critical step when building the model. RSC performs feature ranking before generating rules, and converts the feature ranking to minimal hitting set problem addressed by using genetic algorithm (GA). This is done in classical approaches using Support Vector Machine (SVM) by executing many iterations, each of which removes one useless feature. Compared with those methods, our method can avoid many iterations. In addition, a hybrid genetic algorithm is proposed to increase the convergence speed and decrease the training time of RSC. The models generated by RSC take the form of"IF-THEN" rules, which have the advantage of explication. Tests and comparison of RSC with SVM on DARPA benchmark data showed that for Probe and DoS attacks both RSC and SVM yielded highly accurate results (greater than 99% accuracy on testing set).

  9. Intrusion detection using rough set classification

    Institute of Scientific and Technical Information of China (English)

    张连华; 张冠华; 郁郎; 张洁; 白英彩

    2004-01-01

    Recently machine learning-based intrusion detection approaches have been subjected to extensive researches because they can detect both misuse and anomaly. In this paper, rough set classification (RSC), a modem learning algorithm,is used to rank the features extracted for detecting intrusions and generate intrusion detection models. Feature ranking is a very critical step when building the model. RSC performs feature ranking before generating rules, and converts the feature ranking to minimal hitting set problem addressed by using genetic algorithm (GA). This is done in classical approaches using Support Vector Machine (SVM) by executing many iterations, each of which removes one useless feature. Compared with those methods, our method can avoid many iterations. In addition, a hybrid genetic algorithm is proposed to increase the convergence speed and decrease the training time of RSC. The models generated by RSC take the form of"IF-THEN" rules,which have the advantage of explication. Tests and comparison of RSC with SVM on DARPA benchmark data showed that for Probe and DoS attacks both RSC and SVM yielded highly accurate results (greater than 99% accuracy on testing set).

  10. Intrusion detection using pattern recognition methods

    Science.gov (United States)

    Jiang, Nan; Yu, Li

    2007-09-01

    Today, cyber attacks such as worms, scanning, active attackers are pervasive in Internet. A number of security approaches are proposed to address this problem, among which the intrusion detection system (IDS) appears to be one of the major and most effective solutions for defending against malicious users. Essentially, intrusion detection problem can be generalized as a classification problem, whose goal is to distinguish normal behaviors and anomalies. There are many well-known pattern recognition algorithms for classification purpose. In this paper we describe the details of applying pattern recognition methods to the intrusion detection research field. Experimenting on the KDDCUP 99 data set, we first use information gain metric to reduce the dimensionality of the original feature space. Two supervised methods, the support vector machine as well as the multi-layer neural network have been tested and the results display high detection rate and low false alarm rate, which is promising for real world applications. In addition, three unsupervised methods, Single-Linkage, K-Means, and CLIQUE, are also implemented and evaluated in the paper. The low computational complexity reveals their application in initial data reduction process.

  11. The Innovative Structure Solution for Preventing Salt Intrusion and Retaining Freshwater In Mekong Delta VietNam

    NARCIS (Netherlands)

    Hong, S.T.; Vrijling, J.K.; Stive, M.J.F.

    2013-01-01

    In the Mekong Delta Vietnam, the construction of sluices with the purpose of retaining fresh water and preventing salt water intrusion potentially plays a very important role. However, the structures constructed in small rivers according to local or traditional technology revealed many disadvantages

  12. The Innovative Structure Solution for Preventing Salt Intrusion and Retaining Freshwater In Mekong Delta VietNam

    NARCIS (Netherlands)

    Hong, S.T.; Vrijling, J.K.; Stive, M.J.F.

    2013-01-01

    In the Mekong Delta Vietnam, the construction of sluices with the purpose of retaining fresh water and preventing salt water intrusion potentially plays a very important role. However, the structures constructed in small rivers according to local or traditional technology revealed many disadvantages

  13. Count out your intrusions: effects of verbal encoding on intrusive memories.

    Science.gov (United States)

    Krans, Julie; Naring, Gerard; Becker, Eni S

    2009-11-01

    Peri-traumatic information processing is thought to affect the development of intrusive trauma memories. This study aimed to replicate and improve the study by Holmes, Brewin, and Hennessy (2004, Exp. 3) on the role of peri-traumatic verbal processing in analogue traumatic intrusion development. Participants viewed an aversive film under one of three conditions: counting backwards in 3s ("verbal interference"), verbalising emotions and thoughts ("verbal enhancement"), or without an extra task. A dual-process account of PTSD would predict that verbal interference would increase intrusion frequency compared to no task, whereas verbal enhancement would lead to a decrease. In contrast, mainstream memory theory predicts a decrease in intrusion frequency from any concurrent task that diverts attention away from the trauma film. The main finding was that the verbal interference task led to a decrease in intrusive memories of the film compared to the other two conditions. This finding does not support a dual-process account of PTSD, but is in line with general theories of memory and attention.

  14. Simulation of salinity intrusion along the Georgia and South Carolina coasts using climate-change scenarios

    Science.gov (United States)

    Conrads, Paul A.; Roehl, Edwin A.; Daamen, Ruby C.; Cook, John B.

    2013-01-01

    Potential changes in climate could alter interactions between environmental and societal systems and adversely affect the availability of water resources in many coastal communities. Changes in streamflow patterns in conjunction with sea-level rise may change the salinity-intrusion dynamics of coastal rivers. Several municipal water-supply intakes are located along the Georgia and South Carolina coast that are proximal to the present day saltwater-freshwater interface of tidal rivers. Increases in the extent of salinity intrusion resulting from climate change could threaten the availability of freshwater supplies in the vicinity of these intakes. To effectively manage these supplies, water-resource managers need estimates of potential changes in the frequency, duration, and magnitude of salinity intrusion near their water-supply intakes that may occur as a result of climate change. This study examines potential effects of climate change, including altered streamflow and sea-level rise, on the dynamics of saltwater intrusion near municipal water-supply intakes in two coastal areas. One area consists of the Atlantic Intracoastal Waterway (AIW) and the Waccamaw River near Myrtle Beach along the Grand Strand of the South Carolina Coast, and the second area is on or near the lower Savannah River near Savannah, Georgia. The study evaluated how future sea-level rise and a reduction in streamflows can potentially affect salinity intrusion and threaten municipal water supplies and the biodiversity of freshwater tidal marshes in these two areas. Salinity intrusion occurs as a result of the interaction between three principal forces—streamflow, mean coastal water levels, and tidal range. To analyze and simulate salinity dynamics at critical coastal gaging stations near four municipal water-supply intakes, various data-mining techniques, including artificial neural network (ANN) models, were used to evaluate hourly streamflow, salinity, and coastal water-level data collected

  15. Bibliography on the occurrence and intrusion of saltwater in aquifers along the Atlantic Coast of the United States

    Science.gov (United States)

    Barlow, Paul M.; Wild, Emily C.

    2002-01-01

    Freshwater aquifers along the Atlantic coast of the United States are vulnerable to the intrusion of saltwater from saline waters that bound the aquifers along their seaward margins. Incidences of saltwater intrusion have been documented along the Atlantic coast for more than 100 years. This report provides a bibliography of published literature relating to the occurrence and intrusion of saltwater along the Atlantic coast of the United States, including all of the coastal States from Maine to Florida (including the coast of Florida along the Gulf of Mexico). The bibliography contains 549 references that date from 1896 to 2001. The bibliography contains references to books, journal articles, and government and other technical reports and maps that could be readily obtained through a scientific library. Conference papers and abstracts, unpublished manuscripts, publications in press, newspaper articles, consulting reports, and reports prepared by local or regional water companies or water districts are omitted from the bibliography.

  16. Monitoring and Assessment of Saltwater Intrusion using Geographic Information Systems (GIS), Remote Sensing and Geophysical measurements of Guimaras Island, Philippines

    Science.gov (United States)

    Hernandez, B. C. B.

    2015-12-01

    Degrading groundwater quality due to saltwater intrusion is one of the key challenges affecting many island aquifers. These islands hold limited capacity for groundwater storage and highly dependent on recharge due to precipitation. But its ease of use, natural storage and accessibility make it more vulnerable to exploitation and more susceptible to encroachment from its surrounding oceanic waters. Estimating the extent of saltwater intrusion and the state of groundwater resources are important in predicting and managing water supply options for the community. In Guimaras island, central Philippines, increasing settlements, agriculture and tourism are causing stresses on its groundwater resource. Indications of saltwater intrusion have already been found at various coastal areas in the island. A Geographic Information Systems (GIS)-based approach using the GALDIT index was carried out. This includes six parameters assessing the seawater intrusion vulnerability of each hydrogeologic setting: Groundwater occurrence, Aquifer hydraulic conductivity, Groundwater Level above sea, Distance to shore, Impact of existing intrusion and Thickness of Aquifer. To further determine the extent of intrusion, Landsat images of various thematic layers were stacked and processed for unsupervised classification and electrical resistivity tomography using a 28-electrode system with array lengths of 150 and 300 meters was conducted. The GIS index showed where the vulnerable areas are located, while the geophysical measurements and images revealed extent of seawater encroachment along the monitoring wells. These results are further confirmed by the measurements collected from the monitoring wells. This study presents baseline information on the state of groundwater resources and increase understanding of saltwater intrusion dynamics in island ecosystems by providing a guideline for better water resource management in the Philippines.

  17. Frequency of intrusive luxation in deciduous teeth and its effects.

    Science.gov (United States)

    Carvalho, Vivian; Jacomo, Diana Ribeiro; Campos, Vera

    2010-08-01

    The aims of this study were three-fold: First, to determine the prevalence of partial and total intrusion of the primary anterior teeth. Second, to investigate the sequelae of total and partial intrusive luxation in the primary anterior teeth and in their successors and finally, to establish whether the sequelae on both deciduous and permanent teeth were related to the child's age at the time of the intrusion. Data collected from records of 169 boys and 138 girls, all between the ages of zero and 10 years, who were undergoing treatment during the period of March 1996 to December 2004. The sample was composed of 753 traumatized deciduous teeth, of which 221 presented intrusive luxation injury. Children with ages ranging from one to 4 years were the most affected with falls being the main cause of intrusion. Of all intruded teeth 128 (57.9%) were totally intruded and 93 (42.1%) partially. Pulp necrosis/premature loss and color change were the most frequent sequelae in both total and partial intrusions. Concerning permanent dentition, the most common disturbances were color change and/or enamel hypoplasia. Both types of intrusion caused eruption disturbance. Total intrusion was the most frequent type of intrusive luxation. There was no significant correlation between the child's age at the time of intrusion and the frequency of subsequent sequela on primary injured teeth (P = 0.035), between the age at the time of injury and the developmental disturbances on permanent teeth (P = 0.140).

  18. Simulation of the Vapor Intrusion Process for Non-Homogeneous Soils Using a Three-Dimensional Numerical Model.

    Science.gov (United States)

    Bozkurt, Ozgur; Pennell, Kelly G; Suuberg, Eric M

    2009-01-01

    This paper presents model simulation results of vapor intrusion into structures built atop sites contaminated with volatile or semi-volatile chemicals of concern. A three-dimensional finite element model was used to investigate the importance of factors that could influence vapor intrusion when the site is characterized by non-homogeneous soils. Model simulations were performed to examine how soil layers of differing properties alter soil gas concentration profiles and vapor intrusion rates into structures. The results illustrate difference in soil gas concentration profiles and vapor intrusion rates between homogeneous and layered soils. The findings support the need for site conceptual models to adequately represent the site's geology when conducting site characterizations, interpreting field data and assessing the risk of vapor intrusion at a given site. For instance, in layered geologies, a lower permeability and diffusivity soil layer between the source and building often limits vapor intrusion rates, even if a higher permeability layer near the foundation permits increased soil gas flow rates into the building. In addition, the presence of water-saturated clay layers can considerably influence soil gas concentration profiles. Therefore, interpreting field data without accounting for clay layers in the site conceptual model could result in inaccurate risk calculations. Important considerations for developing more accurate conceptual site models are discussed in light of the findings.

  19. Geophysical characterization of saltwater intrusion in a coastal aquifer: The case of Martil-Alila plain (North Morocco)

    Science.gov (United States)

    Himi, Mahjoub; Tapias, Josefiina; Benabdelouahab, Sara; Salhi, Adil; Rivero, Luis; Elgettafi, Mohamed; El Mandour, Abdenabi; Stitou, Jamal; Casas, Albert

    2017-02-01

    Several factors can affect the quantity and the quality of groundwater resources, but in coastal aquifers seawater intrusion is often the most significant issue regarding freshwater supply. Further, saltwater intrusion is a worldwide issue because about seventy percent of the world's population lives in coastal regions. Generally, fresh groundwater not affected by saltwater intrusion is characterized by low salinity and therefore low electrical conductivity (EC) values. Consequently, high values of EC in groundwater along the coastline are usually associated to seawater intrusion. This effect is amplified if the coastal aquifer is overexploited with a subsequent gradual displacement of the freshwater-saltwater interface towards the continent. Delineation of marine intrusion in coastal aquifers has traditionally relied upon observation wells and collection of water samples. This approach may miss important hydrologic features related to saltwater intrusion in areas where access is difficult and where wells are widely spaced. Consequently, the scarcity of sampling points and sometimes their total absence makes the number of data available limited and most of the time not representative for mapping the spatial and temporal variability of groundwater salinity. In this study, we use a series of geophysical methods for characterizing the aquifer geometry and the extension of saltwater intrusion in the Martil-Alila coastal region (Morocco) as a complement to geological and hydrogeochemical data. For this reason, we carried out three geophysical surveys: Gravity, Electrical Resistivity and Frequency Domain Electromagnetic. The geometry of the basin has been determined from the interpretation of a detailed gravity survey. Electrical resistivity models derived from vertical electrical soundings allowed to characterize the vertical and the lateral extensions of aquifer formations. Finally, frequency domain electromagnetic methods allowed delineating the extension of the

  20. High-resolution insights into episodes of crystallization, hydrothermal alteration and remelting in the Skaergaard intrusive complex

    Science.gov (United States)

    Wotzlaw, Jörn-Frederik; Bindeman, Ilya N.; Schaltegger, Urs; Brooks, C. Kent; Naslund, H. Richard

    2012-11-01

    This paper presents a new high-precision zircon U-Pb geochronological view on the crystallization and assembly process of one of the most important and intensely studied intrusive bodies on Earth—the Skaergaard intrusion in East Greenland. With analytical uncertainties of a few tens of thousands of years, we were able to resolve several important events during cooling of this intrusion. Initial cooling of the shallowly intruded ˜300 km3 of tholeiitic basaltic magma from liquidus to zircon saturation at ˜1000 °C is recorded by a precise zircon crystallization age of 55.960±0.018 Ma of an intercumulus gabbroic pegmatite in the lower portion of the intrusion. Based on this zircon crystallization age and a published cooling model we estimate the "true" age of emplacement to be ˜56.02 Ma. The last portions of Skaergaard appear to crystallize completely ˜100 ka after emplacement as recorded by abundant ˜55.91-55.93 Ma zircons in the Sandwich Horizon (SH), where lower and upper solidification fronts met. Intrusion of an isotopically distinct new magma batch, the ˜600 m thick Basistoppen Sill, into the solidified upper portion of Skaergaard, happened at 55.895±0.018 Ma, suggesting close timing between crystallization of evolved rocks around the SH and intrusion of the Basistoppen Sill. The novel result of this work is the demonstration that zircons in the SH, >100 m below the Basistoppen contact, have a bimodal age distribution, with the youngest population of 55.838±0.019 Ma postdating intrusion of the Basistoppen Sill by 57±37 ka. Oxygen isotope analyses reveal that SH zircons are low and heterogeneous with respect to δ18O. These results support the proposed conclusion that the SH crystallized twice: it was fully crystalline, then hydrothermally-altered by low-δ18O surface waters and subsequently partially remelted, triggered by heat of the Basistoppen Sill. The low-degree partial melt generated during remelting partially migrated upward by intergranular

  1. Sensitivity analysis on parameters and processes affecting vapor intrusion risk.

    Science.gov (United States)

    Picone, Sara; Valstar, Johan; van Gaans, Pauline; Grotenhuis, Tim; Rijnaarts, Huub

    2012-05-01

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion.

  2. Sensitivity analysis on parameters and processes affecting vapor intrusion risk

    KAUST Repository

    Picone, Sara

    2012-03-30

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the vast majority of previous studies, this model accounts for vertical variation of soil water saturation and includes aerobic biodegradation. The attenuation factor (ratio between concentration in the crawl space and source concentration) and the characteristic time to approach maximum concentrations were calculated and compared for a variety of scenarios. These concepts allow an understanding of controlling mechanisms and aid in the identification of critical parameters to be collected for field situations. The relative distance of the source to the nearest gas-filled pores of the unsaturated zone is the most critical parameter because diffusive contaminant transport is significantly slower in water-filled pores than in gas-filled pores. Therefore, attenuation factors decrease and characteristic times increase with increasing relative distance of the contaminant dissolved source to the nearest gas diffusion front. Aerobic biodegradation may decrease the attenuation factor by up to three orders of magnitude. Moreover, the occurrence of water table oscillations is of importance. Dynamic processes leading to a retreating water table increase the attenuation factor by two orders of magnitude because of the enhanced gas phase diffusion. © 2012 SETAC.

  3. Saltwater intrusion in the surficial aquifer system of the Big Cypress Basin, southwest Florida, and a proposed plan for improved salinity monitoring

    Science.gov (United States)

    Prinos, Scott T.

    2013-01-01

    The installation of drainage canals, poorly cased wells, and water-supply withdrawals have led to saltwater intrusion in the primary water-use aquifers in southwest Florida. Increasing population and water use have exacerbated this problem. Installation of water-control structures, well-plugging projects, and regulation of water use have slowed saltwater intrusion, but the chloride concentration of samples from some of the monitoring wells in this area indicates that saltwater intrusion continues to occur. In addition, rising sea level could increase the rate and extent of saltwater intrusion. The existing saltwater intrusion monitoring network was examined and found to lack the necessary organization, spatial distribution, and design to properly evaluate saltwater intrusion. The most recent hydrogeologic framework of southwest Florida indicates that some wells may be open to multiple aquifers or have an incorrect aquifer designation. Some of the sampling methods being used could result in poor-quality data. Some older wells are badly corroded, obstructed, or damaged and may not yield useable samples. Saltwater in some of the canals is in close proximity to coastal well fields. In some instances, saltwater occasionally occurs upstream from coastal salinity control structures. These factors lead to an incomplete understanding of the extent and threat of saltwater intrusion in southwest Florida. A proposed plan to improve the saltwater intrusion monitoring network in the South Florida Water Management District’s Big Cypress Basin describes improvements in (1) network management, (2) quality assurance, (3) documentation, (4) training, and (5) data accessibility. The plan describes improvements to hydrostratigraphic and geospatial network coverage that can be accomplished using additional monitoring, surface geophysical surveys, and borehole geophysical logging. Sampling methods and improvements to monitoring well design are described in detail. Geochemical analyses

  4. Rapid laccolith intrusion driven by explosive volcanic eruption

    Science.gov (United States)

    Castro, Jonathan M.; Cordonnier, Benoit; Schipper, C. Ian; Tuffen, Hugh; Baumann, Tobias S.; Feisel, Yves

    2016-11-01

    Magmatic intrusions and volcanic eruptions are intimately related phenomena. Shallow magma intrusion builds subsurface reservoirs that are drained by volcanic eruptions. Thus, the long-held view is that intrusions must precede and feed eruptions. Here we show that explosive eruptions can also cause magma intrusion. We provide an account of a rapidly emplaced laccolith during the 2011 rhyolite eruption of Cordón Caulle, Chile. Remote sensing indicates that an intrusion began after eruption onset and caused severe (>200 m) uplift over 1 month. Digital terrain models resolve a laccolith-shaped body ~0.8 km3. Deformation and conduit flow models indicate laccolith depths of only ~20-200 m and overpressures (~1-10 MPa) that likely stemmed from conduit blockage. Our results show that explosive eruptions may rapidly force significant quantities of magma in the crust to build laccoliths. These iconic intrusions can thus be interpreted as eruptive features that pose unique and previously unrecognized volcanic hazards.

  5. Corticostriatal circuitry in regulating diseases characterized by intrusive thinking.

    Science.gov (United States)

    Kalivas, Benjamin C; Kalivas, Peter W

    2016-03-01

    Intrusive thinking triggers clinical symptoms in many neuropsychiatric disorders. Using drug addiction as an exemplar disorder sustained in part by intrusive thinking, we explore studies demonstrating that impairments in corticostriatal circuitry strongly contribute to intrusive thinking. Neuroimaging studies have long implicated this projection in cue-induced craving to use drugs, and preclinical models show that marked changes are produced at corticostriatal synapses in the nucleus accumbens during a relapse episode. We delineate an accumbens microcircuit that mediates cue-induced drug seeking becoming an intrusive event. This microcircuit harbors many potential therapeutic targets. We focus on preclinical and clinical studies, showing that administering N-acetylcysteine restores uptake of synaptic glutamate by astroglial glutamate transporters and thereby inhibits intrusive thinking. We posit that because intrusive thinking is a shared endophenotype in many disorders, N-acetylcysteine has positive effects in clinical trials for a variety of neuropsychiatric disorders, including drug addiction, gambling, trichotillomania, and depression.

  6. Multi-agent cooperative intrusion response in mobile adhoc networks

    Institute of Scientific and Technical Information of China (English)

    Yi Ping; Zou Futai; Jiang Xinghao; Li Jianhua

    2007-01-01

    The nature of adhoc networks makes them vulnerable to security attacks. Many security technologies such as intrusion prevention and intrusion detection are passive in response to intrusions in that their countermeasures are only to protect the networks, and there is no automated network-wide counteraction against detected intrusions. the architecture of cooperation intrusion response based multi-agent is propose. The architecture is composed of mobile agents. Monitor agent resides on every node and monitors its neighbor nodes. Decision agent collects information from monitor nodes and detects an intrusion by security policies. When an intruder is found in the architecture, the block agents will get to the neighbor nodes of the intruder and form the mobile firewall to isolate the intruder. In the end, we evaluate it by simulation.

  7. Numerical and physical modeling of cutoff walls against saltwater intrusion

    Science.gov (United States)

    Crestani, Elena; Camporese, Matteo; Salandin, Paolo

    2017-04-01

    Seawater intrusion is a relevant problem for many communities living in small islands, where the amount of fresh water available for human consumption depends on the delicate equilibrium between the natural groundwater recharge from rainfall and the surrounding sea. However, it can represent a significant issue also for coastal regions where groundwater is extracted for water supply: an excessive extraction to meet growing demands for drinking water and irrigation purposes leads to a decrease of seaward flows of fresh water and consequently to an increase of seawater intrusion into coastal aquifers. Cutoff walls represent one of the possible strategies that can be adopted to reduce seawater intrusion into coastal aquifers and to limit the inland progression of the saltwater wedge. In this study, on the basis of several preliminary simulations developed by the SUTRA code, a cutoff wall occluding 70% of the aquifer depth is designed for a physical experiment, whose setup details are reported as follows. The physical model represents the terminal part of a coastal aquifer and consists of a flume 500 cm long, 30 cm wide and 60 cm high, filled for an height of 49 cm with glass beads with a d50 of 0.6 mm and a uniformity coefficient d60/d10 1.5. The resulting porous medium is homogeneous, with porosity of about 0.37 and hydraulic conductivity of about 1.3 10-3 m/s. Upstream from the sandbox, a tank filled by freshwater provides recharge for the aquifer. The downstream tank simulates the sea and red food dye is added to the saltwater to easily visualize the salt wedge. The volume of the downstream tank is about five times the upstream one, and, due to the small filtration discharge, minimizing salt concentration variations due to the incoming freshwater flow. The hydraulic gradient during the tests is constant, due to the fixed water level in the tanks. Water levels and discharged flow rate are continuously monitored. The cutoff wall was realized with sodium bentonite

  8. Network Intrusion Detection based on GMKL Algorithm

    Directory of Open Access Journals (Sweden)

    Li Yuxiang

    2013-06-01

    Full Text Available According to the 31th statistical reports of China Internet network information center (CNNIC, by the end of December 2012, the number of Chinese netizens has reached 564 million, and the scale of mobile Internet users also reached 420 million. But when the network brings great convenience to people's life, it also brings huge threat in the life of people. So through collecting and analyzing the information in the computer system or network we can detect any possible behaviors that can damage the availability, integrity and confidentiality of the computer resource, and make timely treatment to these behaviors which have important research significance to improve the operation environment of network and network service. At present, the Neural Network, Support Vector machine (SVM and Hidden Markov Model, Fuzzy inference and Genetic Algorithms are introduced into the research of network intrusion detection, trying to build a healthy and secure network operation environment. But most of these algorithms are based on the total sample and it also hypothesizes that the number of the sample is infinity. But in the field of network intrusion the collected data often cannot meet the above requirements. It often shows high latitudes, variability and small sample characteristics. For these data using traditional machine learning methods are hard to get ideal results. In view of this, this paper proposed a Generalized Multi-Kernel Learning method to applied to network intrusion detection. The Generalized Multi-Kernel Learning method can be well applied to large scale sample data, dimension complex, containing a large number of heterogeneous information and so on. The experimental results show that applying GMKL to network attack detection has high classification precision and low abnormal practical precision.

  9. Intelligent Intrusion Detection System Model Using Rough Neural Network

    Institute of Scientific and Technical Information of China (English)

    YAN Huai-zhi; HU Chang-zhen; TAN Hui-min

    2005-01-01

    A model of intelligent intrusion detection based on rough neural network (RNN), which combines the neural network and rough set, is presented. It works by capturing network packets to identify network intrusions or malicious attacks using RNN with sub-nets. The sub-net is constructed by detection-oriented signatures extracted using rough set theory to detect different intrusions. It is proved that RNN detection method has the merits of adaptive, high universality,high convergence speed, easy upgrading and management.

  10. Performance Assessment of Network Intrusion-Alert Prediction

    Science.gov (United States)

    2012-09-01

    personnel information, credit card information theft, etc. The focus has shifted to attacks that can cause significant damage. Intrusion detection...Maintaining access Miscellanous Reverse engineering RFID tools Table 3. BackTrack Intrusion-detection System/Intrusion-prevention System Penetration...high processing power. 22 Machine 1’s network interface card connected to the mirroring port on the first port of the Ethernet switch. Machine 2’s

  11. Introduction to gravity currents and intrusions

    CERN Document Server

    Ungarish, Marius

    2009-01-01

    The whole book is well written in a clear and pedagogical general style. … the author has, in my opinion, produced the first comprehensive book entirely devoted to the modeling of gravity currents and intrusions. This book will be particularly useful to graduate and PhD students, as well as to academics and research engineers working in this field. It may be used as a self-consistent document to get a detailed idea of the state of knowledge about a given problem or a guide toward more specialized papers. It is rich with ideas regarding the direction in which further research is warranted. This

  12. Forensic Analysis of Windows Registry Against Intrusion

    Directory of Open Access Journals (Sweden)

    Haoyang Xie

    2012-03-01

    Full Text Available Windows Registry forensics is an important branch of computer and network forensics. Windows Registry is often considered as the heart of Windows Operating Systems because it contains allof the configuration setting of specific users, groups, hardware, software, and networks. Therefore, Windows Registry can be viewed as a gold mine of forensic evidences which could be used in courts. This paper introduces the basics of Windows Registry, describes its structure and its keys and subkeys thathave forensic values. This paper also discusses how the Windows Registry forensic keys can be applied in intrusion detection.

  13. Sulfide intrusion and detoxification in seagrasses ecosystems

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis, tracing sulfur compounds combined with ecosystem parameters we found different spatial, intraspecific and interspecific strategies to cope with sulfidic sediments. 1......) Tolerance, by elimination (eg. Zostera marina); where we found precipitation of sulfide as non-toxic elemental sulfur on the inner wall of the root lacunae. 2) Utilization (eg. Z. marina), where seagrasses detoxify and incorporate sulfides by active uptake and metabolize to sulfate, representing a non...

  14. Impact of Demographic Growth on Seawater Intrusion: Case of the Tripoli Aquifer, Lebanon

    Directory of Open Access Journals (Sweden)

    Omar Kalaoun

    2016-03-01

    Full Text Available Water resources in Mediterranean coastal aquifers are subject to overexploitation leading to an increase in seawater intrusion. Based on the United Nations Environment Program, “UNEP” 75% of people in the world will live in coastal cities by 2020. This is having a major impact on the salinization process. This paper deals with the impact of demographic evolution on seawater intrusion and considers the case of the lower Tripoli aquifer in Lebanon. A numerical model based on the sharp interface approach is implemented using “Freefem++” to access the seawater intrusion. The model is verified against an analytic and a numerical solution. It is calibrated and validated against hydraulic head observations (RMSD = 0.819 m. Then several scenarios of pumping are applied based on available demographic growth rates to quantify the impact on seawater intrusion. The projection scenarios show that if the current pumping rates are maintained while maintaining the demographic evolution, the pumping wells will be salinized within 2 decades in the highly populated areas.

  15. Wavelet Analysis of the Dynamic Characteristics of Saltwater Intrusion in the Beibu Gulf, Southern China

    Science.gov (United States)

    Li, Q.

    2016-12-01

    The Nanliujiang Waterway (NW), a major outlet of the Beibu gulf, is a crucial source of water supply for Beihai City in Southern China. This waterway is frequently affected by saltwater intrusion from the Beibu Gulf of southern China, which has caused serious water shortage in recent years. For the planning and management of water supply at this waterway it is necessary to understand the characteristics of saltwater intrusion particularly in the low flow period of the year. However, as a result of multiple impacts from tide, river discharge, wind, topography, channel bathometry, and some other factors, the saltwater intrusion into this waterway is highly non-linear. In order to account for the non-linear characteristics, the wavelet method was used to analyse the period characteristics of tidal range, river discharge, and salinity and the impact of tidal range and river discharge on the salinity. Results show that the tidal range at Bailong station and the salinity at Beihai-port station both exhibit a stable 13.5-day period and the salinity in the NW is largely impacted by the tidal range during low stream flow periods. River flows from upstream of the waterway don't show any stable period characteristic. It, however, is critical in mitigating the salinity for water supply during saltwater intrusion. A minimum total flow of 2600 m3/s from upstream at Daguangsha and Yinpang stations has been practiced as a threshold for safe water supply. This study has found that the present time when salinity is below the maximum permissible salinity of 238 ml/g for water supply increases as the river discharge from upstream increases and up to 40-60% of the time the salinity at water supply pumping station is below 238 mg/l when the upstream flow is greater than 2600 m3/s. Planning and management of water supply operation at the NW is politically, economically and mostly importantly technically challenging, findings from this study can provide some guidance for operation and

  16. Seawater intrusion policy analysis with a numerical spatially heterogeneous dynamic optimization model

    Science.gov (United States)

    Reinelt, Peter

    2005-05-01

    For more than 50 years, Monterey County and California State officials have pursued without success water policies to halt groundwater overdraft and seawater intrusion in the multilayer confined aquifers underlying arguably the most productive farmland in the United States. This study develops a general dynamic optimization model that emphasizes the institutional and physical characteristics that differentiate this policy problem from other groundwater extraction problems. The solution of the model exhibits heterogeneous spatial distribution of optimal extraction based on spatially distributed extraction cost, pumping cost externality, and seawater intrusion stock externality. Comparison of model results under alternative management regimes elucidates landowner economic incentives, reveals the potential welfare loss of current state policy, and explains much of the history of the political economy of water in Monterey County.

  17. Optimal management of saltwater intrusion in the coastal aquifer of Malia, Crete (Greece), using particle swarm optimization

    Science.gov (United States)

    Karatzas, George P.; Dokou, Zoi

    2015-09-01

    Saltwater intrusion is a common phenomenon in coastal aquifers that can affect the quality of water intended for drinking and irrigation purposes. In order to provide sustainable management options for the coastal aquifer of Malia, located on the Greek island of Crete, a weighted multi-objective optimization methodology is employed. The methodology involves use of the particle swarm optimization algorithm combined with groundwater modelling. The sharp-interface approximation combined with the Ghyben-Herztberg equation is used to estimate the saltwater-intrusion front location. The prediction modelling results show that under the current pumping strategies (over-exploitation), the saltwater-intrusion front will continue to move inland, posing a serious threat to the groundwater quality. The management goal is to maximize groundwater withdrawal rates in the existing pumping wells while inhibiting the saltwater-intrusion front at locations closer to the coastal zone. This is achieved by requiring a minimum hydraulic-head value at pre-selected observation locations. In order to control the saltwater intrusion, a large number of pumping wells must be deactivated and alternative sources of water need to be considered.

  18. Modeling saltwater intrusion in highly heterogeneous coastal aquifers

    Science.gov (United States)

    Safi, Amir; El-Fadel, Mutasem; Doummar, Joanna; Abou Najm, Majdi; Alameddine, Ibrahim

    2016-04-01

    In this study, a 3D variable-density flow and solute transport model SEAWAT was used to examine the impact of macroscopic variation in a soil matrix on widening or narrowing the thickness of the saltwater-freshwater mixing zone. Located along the Eastern Mediterranean (Beirut), the pilot aquifer consists of karstified limestone of Cretaceous age overlain by Upper Tertiary and Quaternary unconsolidated deposits. The model used the advanced pilot-points parameterization coupled with PEST to characterize spatial heterogeneity. Historically simulated water levels were relied upon to reduce potential numerical instabilities induced by insensitive parameters in transient calibration. The latter demonstrated a high degree of heterogeneity in the middle parts of the aquifer and along western coastlines with specification of a high hydraulic conductivity and low storativity in fault networks. The response of the aquifer to seasonal stresses such as climate cycles, pumping rates and recharge rates was manifested as high fluctuations in potentiometric surface due to potential fast flow pathways along faults. The final distribution of saltwater intrusion supports two mechanisms 1) lateral encroachment of recent seawater into the western zone of the aquifer which is of most concern due to high horizontal hydraulic conductivity in the wave direction and 2) upconing in the northwest and southwest of the aquifer due to large vertical hydraulic conductivities that tend to exacerbate the vertical movement of salinity. Acknowledgments This study is part of a program on climate change and seawater intrusion along the Eastern Mediterranean funded by the International Development Research Center (IDRC) of Canada at the American University of Beirut (AUB). Special thanks are extended to Dr. Charlotte Macalister at IDRC for her support and feedback in implementing this program.

  19. Advanced Trace Pattern For Computer Intrusion Discovery

    CERN Document Server

    Rahayu, S Siti; Shahrin, S; Zaki, M Mohd; Faizal, M A; Zaheera, Z A

    2010-01-01

    The number of crime committed based on the malware intrusion is never ending as the number of malware variants is growing tremendously and the usage of internet is expanding globally. Malicious codes easily obtained and use as one of weapon to gain their objective illegally. Hence, in this research, diverse logs from different OSI layer are explored to identify the traces left on the attacker and victim logs in order to establish worm trace pattern to defending against the attack and help revealing true attacker or victim. For the purpose of this paper, it focused on malware intrusion and traditional worm namely sasser worm variants. The concept of trace pattern is created by fusing the attacker's and victim's perspective. Therefore, the objective of this paper is to propose a general worm trace pattern for attacker's, victim's and multi-step (attacker/victim)'s by combining both perspectives. These three proposed worm trace patterns can be extended into research areas in alert correlation and computer forens...

  20. Characterizing and Improving Distributed Intrusion Detection Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Hurd, Steven A; Proebstel, Elliot P.

    2007-11-01

    Due to ever-increasing quantities of information traversing networks, network administrators are developing greater reliance upon statistically sampled packet information as the source for their intrusion detection systems (IDS). Our research is aimed at understanding IDS performance when statistical packet sampling is used. Using the Snort IDS and a variety of data sets, we compared IDS results when an entire data set is used to the results when a statistically sampled subset of the data set is used. Generally speaking, IDS performance with statistically sampled information was shown to drop considerably even under fairly high sampling rates (such as 1:5). Characterizing and Improving Distributed Intrusion Detection Systems4AcknowledgementsThe authors wish to extend our gratitude to Matt Bishop and Chen-Nee Chuah of UC Davis for their guidance and support on this work. Our thanks are also extended to Jianning Mai of UC Davis and Tao Ye of Sprint Advanced Technology Labs for their generous assistance.We would also like to acknowledge our dataset sources, CRAWDAD and CAIDA, without which this work would not have been possible. Support for OC48 data collection is provided by DARPA, NSF, DHS, Cisco and CAIDA members.

  1. A Bayesian Networks in Intrusion Detection Systems

    Directory of Open Access Journals (Sweden)

    M. Mehdi

    2007-01-01

    Full Text Available Intrusion detection systems (IDSs have been widely used to overcome security threats in computer networks. Anomaly-based approaches have the advantage of being able to detect previously unknown attacks, but they suffer from the difficulty of building robust models of acceptable behaviour which may result in a large number of false alarms caused by incorrect classification of events in current systems. We propose a new approach of an anomaly Intrusion detection system (IDS. It consists of building a reference behaviour model and the use of a Bayesian classification procedure associated to unsupervised learning algorithm to evaluate the deviation between current and reference behaviour. Continuous re-estimation of model parameters allows for real time operation. The use of recursive Log-likelihood and entropy estimation as a measure for monitoring model degradation related with behavior changes and the associated model update show that the accuracy of the event classification process is significantly improved using our proposed approach for reducing the missing-alarm.

  2. Seawater intrusion and pumping wells in coastal aquifers

    Science.gov (United States)

    Nadjafzadeh Anvar, Amir; Riva, Monica

    2017-04-01

    Coastal aquifers are affected by seawater intrusion (SWI), this problem is exacerbated by groundwater extractions. In this work, we analyze key parameters affecting pumping wells contamination in costal aquifers. The USGS SUTRA code is employed to solve numerically flow and transport and to characterize SWI under diverse groundwater withdrawal scenarios. We developed two- and three-dimensional variable-density flow and solute transport models, respectively representing the existence of a pumping well barrier and of a single pumping well. The impact of the joint extraction of fresh- and salt- water has also been considered. We then analyzed the effect of (i) the location and pumping rate of fresh- and salt- water pumping wells (ii) the permeability of the aquifer as well as (iii) the transverse and longitudinal dispersivity on the maximum pumping time, tmax. The latter is defined as the maximum freshwater pumping time preventing the well to be contaminated by salt water. Finally we derived empirical equations to be used in practical applications to evaluate tmax as a function of key parameters highlighted.

  3. Research on the dry intrusion accompanying the low vortex precipitation

    Institute of Scientific and Technical Information of China (English)

    YAO; XiuPing; WU; GuoXiong; ZHAO; BingKe; YU; YuBin; YANG; GuiMing

    2007-01-01

    By employing the 6.7μm satellite vapor cloud images and NCEP/NCAR 1°×1° reanalysis datasets, the characteristics and mechanism of the dry intrusion, as well as its impacts on the low vortex precipitation at the Meiyu front are explored in this paper. It is found that the formation,development and maintenance of the low vortex precipitation at the Meiyu front are closely related to the evolution of the dry intrusion. The dry intrusion is characterized by high potential vorticity (PV), low humidity and cold air. The dry intrusion exhibits as an obvious dark zone on vapor cloud images, an area in which atmospheric relative humidity is lower than 60%. However, the features of the dry intrusion on the vapor images are clearer than that of the humidity field, for the former is the digital vapor cloud images with high temporal and spatial resolution, and it can be used to explore the finer characteristics of the development, evolution and supplement of the intrusion during the development of the low vortex. The dry intrusion impacts accompanying the low vortex precipitation at the Meiyu front come from all levels of the troposphere, with the strongest intrusion located at the upper troposphere. The dry and cold air intrudes the vicinity of the low vortex from the upper isentropic surface to the lower one, slanting east-ward from lower to higher level. The low vortex precipitation region is usually situated in front of the dry intrusion where the relative humidity gradient is higher. The research also reveals that the mechanism of the dry intrusion is that the high potential vorticity descends from the upper troposphere to the lower level, therefore, the dry intrusion can be used as an important index of the high PV forcing. To the west of the low vortex precipitation, the upper level northerlies descend across the isentropic surface, then the dry cold advection can trigger the instable development in the midlow troposphere. The dry intru-sion enhances the low vortex

  4. Compositional Convection-Driven Differentiation in the Skaergaard Intrusion: A Reaction- Transport Model

    Science.gov (United States)

    Sonnenthal, E.; McBirney, A.

    2007-12-01

    Considerable debate has focused on the role of thermal versus compositional convection and late-stage melt and volatile migration in the differentiation of layered intrusions, including the Skaergaard Intrusion. The result of these coupled processes is a hierarchy of structures from textural re-equilibration, to mm-scale rhythmic layering, to large-scale mobilization and recrystallization involving melt and volatiles. In the Skaergaard Intrusion, there is evidence that the base of the intrusion crystallized from melts strongly enriched in iron, presumably derived from the walls and/or roof. To investigate the scenario that iron-rich melts migrated from or through the crystallizing walls and ponded on the floor, we developed a two-dimensional reaction-transport model having the projected cross-section of the intrusion. Simulations of coupled flow and reaction of melt, heat, and minerals were performed using the RCTMAG code developed by the authors. Processes include conservation of fluid mass, energy, advective and diffusive multicomponent transport, and crystallization/melting. Crystal-melt equilibria and compositions are treated using distribution coefficients based on literature values or derived from lab and/or field data. Permeability and porosity changes are coupled to crystallization and melting, with the resulting volume changes affecting flow. Simulations show that iron-rich melt develops within the sidewall mush and tends to migrate through the mush toward the base. Compositional convection dominates over thermal convection because heat loss through the walls and roof lead to crystallization and melt compositional changes, affecting density more than temperature. Chemical and thermal diffusion within the mush has subtle effects on mineral compositions and modes, primarily because water and alkalis diffuse faster than other components. The propensity for melt to migrate through the mush is clearly aided by the increase in iron and volatiles, counteracting

  5. Modeling salt intrusion in the San Francisco Estuary prior to anthropogenic influence

    Science.gov (United States)

    Andrews, S. W.; Gross, E. S.; Hutton, P. H.

    2017-08-01

    Anthropogenic changes have dramatically transformed the upper San Francisco Estuary over the past two centuries. Key changes influencing the region's hydrology and hydrodynamics include land use changes, levee construction and channel modifications, upstream reservoir construction, and out-of-basin water exports. In order to examine how these changes have altered the physical characteristics of the estuary, 3-D hydrodynamic models were constructed to study the system in its ;pre-development; condition, prior to significant modern anthropogenic influence, and in its contemporary condition. The pre-development system model was calibrated by varying marsh plain elevations in order to match sparse observations of tidal characteristics; the contemporary system model was calibrated to observed flow, stage, and salinity data. A recent three-year period covering a wide range of flow conditions was used to compare and contrast the hydrodynamic behavior of the two systems. While the contemporary model simulation assumed historical observed boundary conditions, the pre-development model simulation assumed conditions thought to exist prior to the alterations of the past two centuries. The relationship between estuary outflow and the longitudinal distance from the estuary mouth to the 2 psu bottom salinity isohaline (X2) was analyzed. Salt intrusion in the pre-development system was found to be slightly more sensitive to outflow and responded faster to changes in outflow than in the contemporary system. Changes in estuary outflows were responsible for more of the salt intrusion differences between the two systems than were changes in estuary geometry and bathymetry. An analysis of the physical mechanisms contributing to salt intrusion found tidal trapping and other unsteady processes to be more important in the pre-development estuary than in the contemporary one. In both systems, steady processes such as estuarine circulation were strongest during neap tides and unsteady salt

  6. Using state-of-the-art technology to evaluate saltwater intrusion in the Biscayne aquifer of Miami-Dade County, Florida

    Science.gov (United States)

    Prinos, Scott T.

    2014-01-01

    The fresh groundwater supplies of many communities have been adversely affected or limited by saltwater intrusion. An insufficient understanding of the origin of intruded saltwater may lead to inefficient or ineffective water-resource management. A 2008–2012 cooperative U.S. Geological Survey (USGS) and Miami-Dade County study of saltwater intrusion describes state-of-the art technology used to evaluate the origin and distribution of this saltwater.

  7. Young women's experiences of intrusive behavior in 12 countries.

    Science.gov (United States)

    Sheridan, Lorraine; Scott, Adrian J; Roberts, Karl

    2016-01-01

    The present study provides international comparisons of young women's (N = 1,734) self-reported experiences of intrusive activities enacted by men. Undergraduate psychology students from 12 countries (Armenia, Australia, England, Egypt, Finland, India, Indonesia, Italy, Japan, Portugal, Scotland, and Trinidad) indicated which of 47 intrusive activities they had personally experienced. Intrusive behavior was not uncommon overall, although large differences were apparent between countries when women's personal experiences of specific intrusive activities were compared. Correlations were carried out between self-reported intrusive experiences, the Gender Empowerment Measure (GEM), and Hofstede's dimensions of national cultures. The primary associations were between women's experiences of intrusive behavior and the level of power they are afforded within the 12 countries. Women from countries with higher GEM scores reported experiencing more intrusive activities relating to courtship and requests for sex, while the experiences of women from countries with lower GEM scores related more to monitoring and ownership. Intrusive activities, many of them constituent of harassment and stalking, would appear to be widespread and universal, and their incidence and particular form reflect national level gender inequalities.

  8. An improved unsupervised clustering-based intrusion detection method

    Science.gov (United States)

    Hai, Yong J.; Wu, Yu; Wang, Guo Y.

    2005-03-01

    Practical Intrusion Detection Systems (IDSs) based on data mining are facing two key problems, discovering intrusion knowledge from real-time network data, and automatically updating them when new intrusions appear. Most data mining algorithms work on labeled data. In order to set up basic data set for mining, huge volumes of network data need to be collected and labeled manually. In fact, it is rather difficult and impractical to label intrusions, which has been a big restrict for current IDSs and has led to limited ability of identifying all kinds of intrusion types. An improved unsupervised clustering-based intrusion model working on unlabeled training data is introduced. In this model, center of a cluster is defined and used as substitution of this cluster. Then all cluster centers are adopted to detect intrusions. Testing on data sets of KDDCUP"99, experimental results demonstrate that our method has good performance in detection rate. Furthermore, the incremental-learning method is adopted to detect those unknown-type intrusions and it decreases false positive rate.

  9. Specification Mining for Intrusion Detection in Networked Control Systems

    NARCIS (Netherlands)

    Caselli, Marco; Zambon, Emmanuele; Amann, Johanna; Sommer, Robin; Kargl, Frank

    2016-01-01

    This paper discusses a novel approach to specification-based intrusion detection in the field of networked control systems. Our approach reduces the substantial human effort required to deploy a specification-based intrusion detection system by automating the development of its specification rules.

  10. Soft-sensing, non-intrusive multiphase flow meter

    NARCIS (Netherlands)

    Wrobel, K.; Schiferli, W.

    2009-01-01

    For single phase flow meters more and better non-intrusive or even clamp-on meters become available. This allows for a wider use of meters and for easier flow control. As the demand for multiphase meters is increasing, the current aim is to develop a non-intrusive multiphase flow meter. The non-intr

  11. Reinforced Intrusion Detection Using Pursuit Reinforcement Competitive Learning

    Directory of Open Access Journals (Sweden)

    Indah Yulia Prafitaning Tiyas

    2014-06-01

    Full Text Available Today, information technology is growing rapidly,all information can be obtainedmuch easier. It raises some new problems; one of them is unauthorized access to the system. We need a reliable network security system that is resistant to a variety of attacks against the system. Therefore, Intrusion Detection System (IDS required to overcome the problems of intrusions. Many researches have been done on intrusion detection using classification methods. Classification methodshave high precision, but it takes efforts to determine an appropriate classification model to the classification problem. In this paper, we propose a new reinforced approach to detect intrusion with On-line Clustering using Reinforcement Learning. Reinforcement Learning is a new paradigm in machine learning which involves interaction with the environment.It works with reward and punishment mechanism to achieve solution. We apply the Reinforcement Learning to the intrusion detection problem with considering competitive learning using Pursuit Reinforcement Competitive Learning (PRCL. Based on the experimental result, PRCL can detect intrusions in real time with high accuracy (99.816% for DoS, 95.015% for Probe, 94.731% for R2L and 99.373% for U2R and high speed (44 ms.The proposed approach can help network administrators to detect intrusion, so the computer network security systembecome reliable. Keywords: Intrusion Detection System, On-Line Clustering, Reinforcement Learning, Unsupervised Learning.

  12. Network Security using Linux Intrusion Detection System / IJORCS

    Directory of Open Access Journals (Sweden)

    Arul Anitha

    2011-12-01

    Full Text Available Attacks on the nation’s computer infrastructures are becoming an increasingly serious problem. Firewalls provide a certain amount of security, but can be fooled at times by attacks like IP spoofing and the so called authorized users. So an intelligent system that can detect attacks and intrusions is required. The tool GRANT (Global Real-time Analysis of Network Traffic being a Linux based Intrusion Detection System(LIDs, takes the advantage of the security of a Linux box and secures the other nodes in the perimeter of the network. It is capable of detecting intrusions and probes as and when they occur and capable of responding to “already” successful attacks, thus causing minimal or no damage to the entire network. For better performance, this Linux Intrusion Detection System should be part of a defense in depth strategy such as Firewall and Intrusion Prevention.

  13. Intrusive Thoughts Mediate the Association between Neuroticism and Cognitive Function.

    Science.gov (United States)

    Munoz, Elizabeth; Sliwinski, Martin J; Smyth, Joshua M; Almeida, David M; King, Heather A

    2013-11-01

    Although research has established a negative association between trait neuroticism and cognition, little is known about the mechanisms that underlie this relationship. We examined the tendency to experience intrusive thoughts and negative affect as potential mediators of the relationship between neuroticism and cognitive performance. We hypothesized that the tendency to experience intrusive thoughts reflects ineffective attentional control and would account for the relationship between neuroticism and cognitive performance over and above the mediating effect of negative affect. Three hundred seventeen adults (Mage =49.43) completed a series of attention-demanding cognitive tasks as well as self-report measures of intrusive thoughts, negative affect, and neuroticism. Intrusive thoughts mediated the association between trait neuroticism and cognitive performance beyond negative affect. These findings are consistent with the hypothesis that the tendency to experience intrusive thoughts is a mechanism through which trait neuroticism influences cognitive performance.

  14. Intrusion-Tolerant Based Survivable Model of Database System

    Institute of Scientific and Technical Information of China (English)

    ZHUJianming; WANGChao; MAJianfeng

    2005-01-01

    Survivability has become increasingly important with society's increased dependence of critical infrastructures on computers. Intrusiontolerant systems extend traditional secure systems to be able to survive or operate through attacks, thus it is an approach for achieving survivability. This paper proposes survivable model of database system based on intrusion-tolerant mechanisms. The model is built on three layers security architecture, to defense intrusion at the outer layer, to detect intrusion at the middle layer, and to tolerate intrusion at the inner layer. We utilize the techniques of both redundancy and diversity and threshold secret sharing schemes to implement the survivability of database and to protect confidential data from compromised servers in the presence of intrusions. Comparing with the existing schemes, our approach has realized the security and robustness for the key functions of a database system by using the integration security strategy and multiple security measures.

  15. Multi-core Processors based Network Intrusion Detection Method

    Directory of Open Access Journals (Sweden)

    Ziqian Wan

    2012-09-01

    Full Text Available It is becoming increasingly hard to build an intrusion detection system (IDS, because of the higher traffic throughput and the rising sophistication of attacking. Scale will be an important issue to address in the intrusion detection area. For hardware, tomorrow’s performance gains will come from multi-core architectures in which a number of CPU executes concurrently. We take the advantage of multi-core processors’ full power for intrusion detection in this work. We present an intrusion detection system based on the Snort open-source IDS that exploits the computational power of MIPS multi-core architecture to offload the costly pattern matching operations from the CPU, and thus increase the system’s processing throughput. A preliminary experiment demonstrates the potential of this system. The experiment results indicate that this method can be used effectively to speed up intrusion detection systems.

  16. Coastal Marsh Monitoring for Persistent Saltwater Intrusion

    Science.gov (United States)

    Hall, Callie M.

    2008-01-01

    This viewgraph presentation reviews NASA's work on the project that supports the Gulf of Mexico Alliance (GOMA) Governors Action Plan to monitor the coastal wetlands for saltwater intrusion. The action items that relate to the task are: (1) Obtain information on projected relative sea level rise, subsidence, and storm vulnerability to help prioritize conservation projects, including restoration, enhancement, and acquisition, and (2) Develop and apply ecosystem models to forecast the habitat structure and succession following hurricane disturbance and changes in ecological functions and services that impact vital socio-economic aspects of coastal systems. The objectives of the program are to provide resource managers with remote sensing products that support ecosystem forecasting models requiring salinity and inundation data. Specifically, the proposed work supports the habitat-switching modules in the Coastal Louisiana Ecosystem Assessment and Restoration (CLEAR) model, which provides scientific evaluation for restoration management.

  17. Multimodal Evolution Approach to Multidimensional Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    Weng Guang'an; Yu Shengsheng; Zhou Jingli

    2006-01-01

    An artificial immunity based multimodal evolution algorithm is developed to generate detectors with variable coverage for multidimensional intrusion detection. In this algorithm, a proper fitness function is used to drive the detectors to fill in those detection holes close to self set or among self spheres, and genetic algorithm is adopted to reduce the negative effects that different distribution of self imposes on the detector generating process. The validity of the algorithm is tested with spherical and rectangular detectors,respectively, and experiments performed on two real data sets ( machine learning database and DAPRA99) indicate that the proposed algorithm can obtain good results on spherical detectors, and that its performances in detection rate, false alarm rate, stability, time cost, and adaptability to incomplete training set on spherical detectors are all better than on rectangular ones.

  18. Introduction To Intrusion Detection System Review

    Directory of Open Access Journals (Sweden)

    Rajni Tewatia

    2015-05-01

    Full Text Available Abstract Security of a network is always an important issue. With the continuously growing network the basic security such as firewall virus scanner is easily deceived by modern attackers who are experts in using software vulnerabilities to achieve their goals. For preventing such attacks we need even smarter security mechanism which act proactively and intelligently. Intrusion Detection System is the solution of such requirement. Many techniques have been used to implement IDS. These technique basically used in the detector part of IDS such as Neural Network Clustering Pattern Matching Rule Based Fuzzy Logic Genetic Algorithms and many more. To improve the performance of an IDS these approaches may be used in combination to build a hybrid IDS so that benefits of two o more approaches may be combined.

  19. Predicting salt intrusion into freshwater aquifers resulting from CO2 injection – A study on the influence of conservative assumptions

    DEFF Research Database (Denmark)

    Walter, Lena; Binning, Philip John; Class, Holger

    2013-01-01

    Brine migration and saltwater intrusion into freshwater aquifers are among the hazards which may result from injecting CO2 into deep saline formations. Comprehensive risk assessment should include estimates of the salinization of freshwater aquifers, preferably based on numerical simulation results...... to an underestimation of hazards. This study compares two conceptual model approaches for the numerical simulation of brine-migration scenarios through a vertical fault and salt intrusion into a fresh water aquifer. The first approach calculates salt discharge into freshwater using an immiscible two-phase model...

  20. Cooling of an igneous dike 20 yr after intrusion

    Science.gov (United States)

    Connor, C. B.; Lichtner, P. C.; Conway, F. M.; Hill, B. E.; Ovsyannikov, A. A.; Federchenko, I.; Doubik, Yu.; Shapar, V. N.; Taran, Yu. A.

    1997-08-01

    The 1975 Tolbachik, Kamchatka, Russia, eruption resulted in the formation of three basaltic cinder cones. During this eruption, shallow dike injection into a nearby cinder cone, Cone 1004, caused deformation and slumping of the cone. In 1995, temperatures at 2 m depth, electromagnetic anomalies, and geologic units were mapped on the slump block. These data reveal details about the cooling rates of a shallow dike in the slump block, including (1) measured temperatures as much as 475 °C, (2) temperatures greater than 200 °C along a 160-m-long and 30-m-wide zone that trends oblique to bedding, (3) a low resistivity zone at 80 m depth that may delimit a larger intrusion beneath the shallow dike, (4) a dry zone extending 15 20 m from the axis of the thermal anomaly, and (5) a condensation zone beyond this dry-out zone, characterized by steaming ground and high convective heat flux. Analytic models indicate that the surprisingly high temperatures persist because of the low thermal diffusivity of the scoria into which the dike is injected, a direct result of the scoria's high porosity. Two-phase nonisothermal flow models suggest that the observed patterns of dry-out and condensation are expected for small volume fractions of water in the scoria (≤10%). Thus, field observations from Tolbachik provide a graphic example of the roles of rock thermophysical properties and water in the unsaturated zone on rates of dike cooling.

  1. Resistivity imaging reveals complex pattern of saltwater intrusion along Monterey coast

    Science.gov (United States)

    Goebel, Meredith; Pidlisecky, Adam; Knight, Rosemary

    2017-08-01

    Electrical Resistivity Tomography data were acquired along 40 km of the Monterey Bay coast in central California. These data resulted in electrical resistivity images to depths of approximately 280 m.b.s.l., which were used to understand the distribution of freshwater and saltwater in the subsurface, and factors controlling this distribution. The resulting resistivity sections were interpreted in conjunction with existing data sets, including well logs, seismic reflection data, geologic reports, hydrologic reports, and land use maps from the region. Interpretation of these data shows a complex pattern of saltwater intrusion resulting from geology, pumping, and recharge. The resistivity profiles were used to identify geological flow conduits and barriers such as palaeo-channels and faults, localized saltwater intrusion from individual pumping wells, infiltration zones of surface fresh and brackish water, and regions showing improvements in water quality due to management actions. The use of ERT data for characterizing the subsurface in this region has led to an understanding of the spatial distribution of freshwater and saltwater at a level of detail unattainable with the previously deployed traditional well based salinity mapping and monitoring techniques alone. Significant spatial variability in the extent and geometry of intrusion observed in the acquired data highlights the importance of adopting continuous subsurface characterization methods such as this one.

  2. Using a time lapse microgravity model for mapping seawater intrusion around Semarang

    Science.gov (United States)

    Supriyadi, Khumaedi, Yusuf, M.; Agung, W.

    2016-03-01

    A modeling of time-lapse microgravity anomaly due to sea water intrusion has been conducted. It used field data of aquifer cross section, aquifer thickness and lithology of research area. Those data were then processed using Grav3D and Surfer. Modeling results indicated that the intrusion of sea water resulting in a time-lapse microgravity anomalies of 0.12 to 0.18 mGal, at soil layer density of 0.15 g/cm3 to 0.3 g/cm3 and at depth of 30 to 100 m. These imply that the areas experiencing seawater intrusion were Tanjung Mas, SPBE Bandarharjo, Brass, Old Market Boom and Johar as the microgravity measured there were in the range of 0.12 to 0.18 mGal and the density contrast were at 0.15 g/cm3 to 0.28 g/cm3. Areas that experienced fluid reduction were Puri Anjasmoro, Kenconowungu and Puspowarno with microgravity changes from -0.06 mGal to -0.18 mGal.

  3. A modeling study of saltwater intrusion in the Andarax delta area using multiple data sources

    DEFF Research Database (Denmark)

    Antonsson, Arni Valur; Engesgaard, Peter Knudegaard; Jorreto, Sara;

    In groundwater model development, construction of the conceptual model is one of the (initial and) critical aspects that determines the model reliability and applicability in terms of e.g. system (hydrogeological) understanding, groundwater quality predictions, and general use in water resources...... the understanding of the investigated system. A density dependent saltwater intrusion model has been established for the coastal zone of the Andarax aquifer, SE Spain, with the aim of obtaining a coherent (conceptual) understanding of the area. Recently drilled deep boreholes in  the Andarax delta revealed a far...... reaching saltwater intrusion in the area. Furthermore, the geological information obtained from these boreholes laid a foundation for a new hydrogeological conceptual model of the area, which we aim to assess in this simulation study.Appraisal of the conceptual model of the Andarax delta area is conducted...

  4. Numerical modelling of seawater intrusion in Shenzhen (China) using a 3D densitydependent model including tidal effects

    Indian Academy of Sciences (India)

    Wei Lu; Qingchun Yang; Jordi D Martín; Ricardo Juncosa

    2013-04-01

    During the 1990s, groundwater overexploitation has resulted in seawater intrusion in the coastal aquifer of the Shenzhen city, China. Although water supply facilities have been improved and alleviated seawater intrusion in recent years, groundwater overexploitation is still of great concern in some local areas. In this work we present a three-dimensional density-dependent numerical model developed with the FEFLOW code, which is aimed at simulating the extent of seawater intrusion while including tidal effects and different groundwater pumping scenarios. Model calibration, using waterheads and reported chloride concentration, has been performed based on the data from 14 boreholes, which were monitored from May 2008 to December 2009. A fairly good fitness between the observed and computed values was obtained by a manual trial-and-error method. Model prediction has been carried out forward 3 years with the calibrated model taking into account high, medium and low tide levels and different groundwater exploitation schemes. The model results show that tide-induced seawater intrusion significantly affects the groundwater levels and concentrations near the estuarine of the Dasha river, which implies that an important hydraulic connection exists between this river and groundwater, even considering that some anti-seepage measures were taken in the river bed. Two pumping scenarios were considered in the calibrated model in order to predict the future changes in the water levels and chloride concentration. The numerical results reveal a decreased tendency of seawater intrusion if groundwater exploitation does not reach an upper bound of about 1.32 × 104 m3/d. The model results provide also insights for controlling seawater intrusion in such coastal aquifer systems.

  5. Multiple subtropical stratospheric intrusions over Reunion Island: Observational, Lagrangian, and Eulerian numerical modeling approaches

    Science.gov (United States)

    Vérèmes, H.; Cammas, J.-P.; Baray, J.-L.; Keckhut, P.; Barthe, C.; Posny, F.; Tulet, P.; Dionisi, D.; Bielli, S.

    2016-12-01

    Signatures of multiple stratospheric intrusions were observed on simultaneous and collocated ozone and water vapor profiles retrieved by lidars and radiosondes at the Maïdo Observatory, Reunion Island (21°S, 55°E, 2160 m above sea level), during MAïdo LIdar Calibration CAmpaign in April 2013. A singular structure of the ozone vertical profile with three peaks (in excess of 90 ppbv, at 8, 10, and 13 km altitude) embedded in a thick dry layer of air suggested stratospheric intrusions with multiple origins. The hypothesis is corroborated by a synoptic analysis based on re-analyses. European Centre for Medium-Range Weather Forecasts ERA-Interim temporal series associated with 5 days Lagrangian back trajectories initialized on each ozone peak allows to capture their stratospheric origin. The ozone peak at the lowest altitude is associated with an irreversible tropopause folding process along the polar jet stream during an extratropical cutoff low formation. Simultaneous lidar water vapor profiles of this peak show that the anticorrelation with ozone has been removed, due to mixing processes. Back trajectories indicate that the two other ozone peaks observed at higher altitudes are associated with the dynamics of the subtropical jet stream and the lower stratosphere. The observations confirm the recent stratospheric origins. The highest ozone peak is explained by the horizontal distribution of the intrusion. Use of a Lagrangian Reverse Domain Filling model and of the Meso-NH Eulerian mesoscale model with a passive stratospheric tracer allow to further document the stratosphere-troposphere transport processes and to describe the detailed potential vorticity and ozone structures in which are embedded in the observed multiple stratospheric intrusions.

  6. Saltwater intrusion into tidal freshwater marshes alters the biogeochemical processing of organic carbon

    Directory of Open Access Journals (Sweden)

    S. C. Neubauer

    2013-07-01

    Full Text Available Environmental perturbations in wetlands affect the integrated plant-microbial-soil system, causing biogeochemical responses that can manifest at local to global scales. The objective of this study was to determine how saltwater intrusion affects carbon mineralization and greenhouse gas production in coastal wetlands. Working with tidal freshwater marsh soils that had experienced roughly 3.5 yr of in situ saltwater additions, we quantified changes in soil properties, measured extracellular enzyme activity associated with organic matter breakdown, and determined potential rates of anaerobic carbon dioxide (CO2 and methane (CH4 production. Soils from the field plots treated with brackish water had lower carbon content and higher C : N ratios than soils from freshwater plots, indicating that saltwater intrusion reduced carbon availability and increased organic matter recalcitrance. This was reflected in reduced activities of enzymes associated with the hydrolysis of cellulose and the oxidation of lignin, leading to reduced rates of soil CO2 and CH4 production. The effects of long-term saltwater additions contrasted with the effects of short-term exposure to brackish water during three-day laboratory incubations, which increased rates of CO2 production but lowered rates of CH4 production. Collectively, our data suggest that the long-term effect of saltwater intrusion on soil CO2 production is indirect, mediated through the effects of elevated salinity on the quantity and quality of autochthonous organic matter inputs to the soil. In contrast, salinity, organic matter content, and enzyme activities directly influence CH4 production. Our analyses demonstrate that saltwater intrusion into tidal freshwater marshes affects the entire process of carbon mineralization, from the availability of organic carbon through its terminal metabolism to CO2 and/or CH4, and illustrate that long-term shifts in biogeochemical functioning are not necessarily consistent

  7. The role of stress during memory reactivation on intrusive memories.

    Science.gov (United States)

    Cheung, Jessica; Garber, Benjamin; Bryant, Richard A

    2015-09-01

    Intrusive memories are unwanted recollections that maintain distress in psychological disorders. Increasing evidence suggests that memories that are reactivated through retrieval become temporarily vulnerable to environmental or pharmacological manipulation, including changes in levels of circulating stress hormones. This study investigated the influence of stress during memory reactivation of an emotionally arousing trauma film on subsequent intrusive memories. Three groups of participants (N=63) viewed a trauma film depicting a serious car accident at baseline. Two days later (Time 2), one group received a reactivation induction following a socially evaluated cold pressor test (SECPT; Stress/Reactivation condition), whilst the second group reactivated the memory after a control procedure (Reactivation condition). A third group underwent the SECPT but was not asked to reactivate memory of the trauma film (Stress condition). Two days later (Time 3), all participants received a surprise cued memory recall test and intrusions questionnaire which they completed online. Results showed that those in the Stress/Reactivation group had higher intrusions scores than the other two groups, suggesting that acute stress promotes intrusive memories only when the memory trace is reactivated shortly afterwards. Increased cortisol predicted enhanced intrusive experiences in the Stress/Reactivation condition but not in the other conditions. This pattern of results suggests that acute stress during the reactivation of emotional material impacts on involuntary emotional memories. These findings suggest a possible explanation for the mechanism underlying the maintenance of intrusive memories in clinical disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. A Frequency-Based Approach to Intrusion Detection

    Directory of Open Access Journals (Sweden)

    Mian Zhou

    2004-06-01

    Full Text Available Research on network security and intrusion detection strategies presents many challenging issues to both theoreticians and practitioners. Hackers apply an array of intrusion and exploit techniques to cause disruption of normal system operations, but on the defense, firewalls and intrusion detection systems (IDS are typically only effective in defending known intrusion types using their signatures, and are far less than mature when faced with novel attacks. In this paper, we adapt the frequency analysis techniques such as the Discrete Fourier Transform (DFT used in signal processing to the design of intrusion detection algorithms. We demonstrate the effectiveness of the frequency-based detection strategy by running synthetic network intrusion data in simulated networks using the OPNET software. The simulation results indicate that the proposed intrusion detection strategy is effective in detecting anomalous traffic data that exhibit patterns over time, which include several types of DOS and probe attacks. The significance of this new strategy is that it does not depend on the prior knowledge of attack signatures, thus it has the potential to be a useful supplement to existing signature-based IDS and firewalls.

  9. Experimental modelling of ground deformation associated with shallow magma intrusions

    Science.gov (United States)

    Galland, O.

    2012-04-01

    Active volcanoes experience ground deformation as a response to the dynamics of underground magmatic systems. The analysis of ground deformation patterns may provide important constraints on the dynamics and shape of the underlying volcanic plumbing systems. Nevertheless, these analyses usually take into account simplistic shapes (sphere, dykes, sills) and the results cannot be verified as the modelled systems are buried. In this contribution, I will present new results from experimental models of magma intrusion, in which both the evolution of ground deformation during intrusion and the shape of the underlying intrusion are monitored in 3D. The models consisted of a molten vegetable oil, simulating low viscosity magma, injected into cohesive fine-grained silica flour, simulating the brittle upper crust; oil injection resulted is sheet intrusions (dykes, sills and cone sheets). The initial topography in the models was flat. While the oil was intruding, the surface of the models slightly lifted up to form a smooth relief, which was mapped through time. After an initial symmetrical development, the uplifted area developed asymmetrically; at the end of the experiments, the oil always erupted at the steepest edge of the uplifted area. After the experiment, the oil solidified, the intrusion was excavated and the shape of its top surface mapped. The comparison between the uplifted zone and the underlying intrusions showed that (1) the complex shapes of the uplifted areas reflected the complex shapes of the underlying intrusions, (2) the time evolution of the uplifted zone was correlated with the evolution of the underlying intrusion, and (3) the early asymmetrical evolution of the uplifted areas can be used to predict the location of the eruption of the oil. The experimental results also suggest that complex intrusion shapes (inclined sheet, cone sheet, complex sill) may have to be considered more systematically in analyses of ground deformation patterns on volcanoes.

  10. Geophysical and geochemical studies to delineate seawater intrusion in Bagoush area, Northwestern coast, Egypt

    Science.gov (United States)

    Eissa, Mustafa A.; Mahmoud, Hussein Hosni; Shouakar-Stash, Orfan; El-Shiekh, Abdelfattah; Parker, Beth

    2016-09-01

    Coastal aquifers are the main source for sustainable freshwater in many arid and semi-arid regions around the earth. In such regions, groundwater extraction far exceeds the natural replenishment rates due to additional demands on groundwater resources especially in the last few decades. The characterization of the seawater intrusion in the Baghoush area along the northwestern coast of Egypt assesses the risk of seawater intrusion for the purpose of managing the groundwater resources in coastal areas. The (SI) in the oolitic Pleistocene aquifer is affected by several natural factors, including the drainage patterns, geological structures, distance from the sea and the manipulation of groundwater. Electrical Resistivity Tomography (ERT) has been implemented to identify the geometry of the brackish/saline water interface and to map the distribution of brackish water zone floating over the denser saline water. Seven 2-D resistivity imaging profiles were conducted using a Wenner array with different electrode distance spacings. The inverse resistivity models of these profiles indicate that these profiles are composed of three zones: the upper dry zone, the middle brackish water zone, and the lower saline water zone. The thickness of the brackish groundwater zone decreases toward the sea and the resistivity decreases with depth due to increase in water salinity. Water table along these profiles decreases from south to north, which indicates that groundwater flow is from south (inland) to north (sea). Groundwater chemistry and stable isotopes were used to determine the fresh groundwater recharge source(s), to identify mixing of different groundwaters, to evaluate seawater intrusion zone along the coast, and to investigate the upwelling of deep saline groundwater underneath the brackish zone. The recharge of fresh groundwater originates from the mountain watershed located upstream as well as the annual rainfall; however, seawater is the main source of groundwater

  11. Saltwater intrusion in the Floridan aquifer, coastal Citrus and Hernando Counties, Florida, 1975

    Science.gov (United States)

    Mills, L.R.; Ryder, Paul D.

    1977-01-01

    The coastal parts of Citrus and Hernando Counties, Fla., are undergoing extensive urban development along U.S. Highway 19. The Floridan aquifer, a thick sequence of limestone and dolomite , is the principal source of water supply for the coastal parts of these two counties. The construction of canals that penetrate the Floridan aquifer, deficient rainfall during 1964-75, and pumping of ground water, have caused saltwater to intrude the aquifer. A map shows the inland extend of that intrusion as of 1975. The report is based on field data collected in 1964, 1973, and 1975. (Woodard-USGS)

  12. Simulating spatial adaption of groundwater pumping on seawater intrusion in coastal regions

    Science.gov (United States)

    Grundmann, Jens; Ladwig, Robert; Schütze, Niels; Walther, Marc

    2016-04-01

    Coastal aquifer systems are used intensively to meet the growing demands for water in those regions. They are especially at risk for the intrusion of seawater due to aquifer overpumping, limited groundwater replenishment and unsustainable groundwater management which in turn also impacts the social and economical development of coastal regions. One example is the Al-Batinah coastal plain in northern Oman where irrigated agriculture is practiced by lots of small scaled farms in different distances from the sea, each of them pumping their water from coastal aquifer. Due to continuous overpumping and progressing saltwater intrusion farms near the coast had to close since water for irrigation got too saline. For investigating appropriate management options numerical density dependent groundwater modelling is required which should also portray the adaption of groundwater abstraction schemes on the water quality. For addressing this challenge a moving inner boundary condition is implemented in the numerical density dependent groundwater model which adjusts the locations for groundwater abstraction according to the position of the seawater intrusion front controlled by thresholds of relative chloride concentration. The adaption process is repeated for each management cycle within transient model simulations and allows for considering feedbacks with the consumers e.g. the agriculture by moving agricultural farms more inland or towards the sea if more fertile soils at the coast could be recovered. For finding optimal water management strategies efficiently, the behaviour of the numerical groundwater model for different extraction and replenishment scenarios is approximated by an artificial neural network using a novel approach for state space surrogate model development. Afterwards the derived surrogate is coupled with an agriculture module within a simulation based water management optimisation framework to achieve optimal cropping pattern and water abstraction schemes

  13. Amphibole-rich intrusive mafic and ultramafic rocks in arc settings: implications for the H2O budget

    Science.gov (United States)

    Tiepolo, M.; Langone, A.; Morishita, T.; Esna-Ashari, A.; Tribuzio, R.

    2011-12-01

    budget. The average H2O content measured in amphibole from amphibole-rich mafic and ultramafic intrusive rocks is about 1.5 wt.%. These rocks, with up to 90 vol% of amphibole, may thus subtract large amounts of H2O to their parental melts and act as water reservoirs in the arc crust.

  14. Temporal moisture content variability beneath and external to a building and the potential effects on vapor intrusion risk assessment.

    Science.gov (United States)

    Tillman, Fred D; Weaver, James W

    2007-06-15

    Migration of vapors from organic chemicals residing in the subsurface into overlying buildings is known as vapor intrusion. Because of the difficulty in evaluating vapor intrusion by indoor air sampling, models are often employed to determine if a potential indoor inhalation exposure pathway exists and, if such a pathway is complete, whether long-term exposure increases the occupants' risk for cancer or other toxic effects to an unacceptable level. For site-specific vapor intrusion assessments, moisture content is, at times, determined from soil cores taken in open spaces between buildings. However, there is little published information on how moisture content measured outside a building structure compares with the moisture content directly beneath the building - where the values are most critical for vapor intrusion assessments. This research begins to address these issues by investigating the movement of soil moisture next to and beneath a building at a contaminated field site and determining the effect on vapor intrusion risk assessment. A two-dimensional, variably-saturated water flow model, HYDRUS-2D, is used with 2 years of hourly, local rainfall data to simulate subsurface moisture content in the vicinity of a hypothetical 10 x 10-m building slab at a contaminated field site. These moisture content values are used in vapor intrusion risk assessment simulations using the Johnson and Ettinger model with instantaneous and averaged moisture contents. Results show that vapor intrusion risk assessments based on moisture content determined from soil cores taken external to a building structure may moderately-to-severely underestimate the vapor intrusion risk from beneath the structure. Soil under the edges of a slab may be influenced by rainfall events and may show reduced vapor intrusion risk as a consequence. Data from a building instrumented with subslab moisture probes showed results similar to the modeling, but with a smaller difference between the subslab and

  15. Temporal moisture content variability beneath and external to a building and the potential effects on vapor intrusion risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Tillman, Fred D. [National Research Council (United States); U.S. Environmental Protection Agency, National Exposure Research Laboratory, Ecosystems Research Division, 960 College Station Road, Athens, GA 30605-2700 (United States); Weaver, James W. [U.S. Environmental Protection Agency, National Exposure Research Laboratory, Ecosystems Research Division, 960 College Station Road, Athens, GA 30605-2700 (United States)]. E-mail: Weaver.Jim@epa.gov

    2007-06-15

    Migration of vapors from organic chemicals residing in the subsurface into overlying buildings is known as vapor intrusion. Because of the difficulty in evaluating vapor intrusion by indoor air sampling, models are often employed to determine if a potential indoor inhalation exposure pathway exists and, if such a pathway is complete, whether long-term exposure increases the occupants' risk for cancer or other toxic effects to an unacceptable level. For site-specific vapor intrusion assessments, moisture content is, at times, determined from soil cores taken in open spaces between buildings. However, there is little published information on how moisture content measured outside a building structure compares with the moisture content directly beneath the building - where the values are most critical for vapor intrusion assessments. This research begins to address these issues by investigating the movement of soil moisture next to and beneath a building at a contaminated field site and determining the effect on vapor intrusion risk assessment. A two-dimensional, variably-saturated water flow model, HYDRUS-2D, is used with 2 years of hourly, local rainfall data to simulate subsurface moisture content in the vicinity of a hypothetical 10 x 10-m building slab at a contaminated field site. These moisture content values are used in vapor intrusion risk assessment simulations using the Johnson and Ettinger model with instantaneous and averaged moisture contents. Results show that vapor intrusion risk assessments based on moisture content determined from soil cores taken external to a building structure may moderately-to-severely underestimate the vapor intrusion risk from beneath the structure. Soil under the edges of a slab may be influenced by rainfall events and may show reduced vapor intrusion risk as a consequence. Data from a building instrumented with subslab moisture probes showed results similar to the modeling, but with a smaller difference between the

  16. Intrusion detection in wireless ad-hoc networks

    CERN Document Server

    Chaki, Nabendu

    2014-01-01

    Presenting cutting-edge research, Intrusion Detection in Wireless Ad-Hoc Networks explores the security aspects of the basic categories of wireless ad-hoc networks and related application areas. Focusing on intrusion detection systems (IDSs), it explains how to establish security solutions for the range of wireless networks, including mobile ad-hoc networks, hybrid wireless networks, and sensor networks.This edited volume reviews and analyzes state-of-the-art IDSs for various wireless ad-hoc networks. It includes case studies on honesty-based intrusion detection systems, cluster oriented-based

  17. Novel Hybrid Intrusion Detection System For Clustered Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Hichem Sedjelmaci

    2011-08-01

    Full Text Available Wireless sensor network (WSN is regularly deployed in unattended and hostile environments. The WSN isvulnerable to security threats and susceptible to physical capture. Thus, it is necessary to use effective mechanisms to protect the network. It is widely known, that the intrusion detection is one of the mostefficient security mechanisms to protect the network against malicious attacks or unauthorized access. In this paper, we propose a hybrid intrusion detection system for clustered WSN. Our intrusion framework uses a combination between the Anomaly Detection based on support vector machine (SVM and the Misuse Detection. Experiments results show that most of routing attacks can be detected with low falsealarm.

  18. Spatial distribution of saline water and possible sources of intrusion ...

    African Journals Online (AJOL)

    user

    acidification, heavy metal contamination, organic pollution ... freshwater fishes frequently invade estuaries, especially .... Dry and wet season pH variation from Lagos lagoon via Epe and Lekki lagoons to .... respectively, over a period of two years in Lekki lagoon. .... resulting in high phytoplankton production, which serves.

  19. Geophysical study of saline water intrusion in Lagos municipality

    African Journals Online (AJOL)

    aghomotsegin

    3Department of Physics, Adeyemi College of Education, Ondo, Ondo State, Nigeria. Accepted 14 .... forms a multi-aquifer system consisting of three aquifer horizons ... classifications of Zohdy and Martin (1993) and modified by Ibrahim.

  20. Assessing the risk of saltwater intrusion in coastal aquifers

    Science.gov (United States)

    Klassen, J.; Allen, D. M.

    2017-08-01

    In coastal regions, the quality of groundwater can be compromised due to saltwater intrusion (SWI) caused by natural (sea level rise (SLR) and storm surge) and anthropogenic (pumping) hazards. The goal of this research was to develop and test an approach for assessing the risk of SWI in coastal aquifers. The Gulf Islands in British Columbia (BC) was the case study area. The vulnerability of the bedrock aquifers to SWI was assessed spatially by mapping hazards in combination with the aquifer susceptibility. Climate change related hazards, including SLR and storm surge overwash, were integrated into floodplain maps for each island using projected SLR data for 2100 in combination with estimated storm surge levels based on data collected over a forty year period. When combined with maps showing the density of pumping wells, coastal zones that may be at higher risk of SWI were identified for this particular coastal area of BC. Hazards due to pumping have the greatest influence on the vulnerability. Risk was evaluated spatially using an economic valuation of loss - here replacement of a water supply. The combination of chemical indicators of SWI and risk assessment maps are potentially useful tools for identifying areas vulnerable to SWI, and these tools can be used to improve decision-making related to monitoring and community development for coastal areas, thereby increasing resilience.

  1. Vapor intrusion from entrapped NAPL sources and groundwater plumes

    Science.gov (United States)

    Illangasekare, Tissa H.; Sakaki, Toshihiro; Christ, John; Petri, Bejamin; Sauck, Carolyn; Cihan, Abdullah

    2010-05-01

    Volatile organic compounds (VOC) are commonly found entrapped as non-aqueous phase liquids (NAPLs) in the soil pores or dissolved in groundwater at industrial waste sites and refineries. Vapors emitted from these contaminant sources readily disperse into the atmosphere, into air-filled void spaces within the soil, and migrate below surface structures, leading to the intrusion of contaminant vapors into indoor air through basements and other underground structures. This process referred to as vapor intrusion (VI) represents a potential threat to human health, and is a possible exposure pathway of concern to regulatory agencies. To assess whether this exposure pathway is present, remediation project managers often rely in part on highly simplified screening level models that do not take into consideration the complex flow dynamics controlled by subsurface heterogeneities and soil moisture conditions affected by the mass and heat flux boundary conditions at the land/atmospheric interface. A research study is under way to obtain an improved understanding of the processes and mechanisms controlling vapor generation from entrapped NAPL sources and groundwater plumes, their subsequent migration through the subsurface, and their attenuation in naturally heterogeneous vadose zones under various natural physical, climatic, and geochemical conditions. Experiments conducted at multiple scales will be integrated with analytical and numerical modeling and field data to test and validate existing VI theories and models. A set of preliminary experiments where the fundamental process of vapor generation from entrapped NAPL sources and dissolved plumes under fluctuating water were investigated in small cells and two-dimensional test tanks. In another task, intermediate scale experiments were conducted to generate quantitative data on how the heat and mass flux boundary conditions control the development of dynamic VI pathways. The data from the small cell and tank experiments were

  2. Towards Reliable Evaluation of Anomaly-Based Intrusion Detection Performance

    Science.gov (United States)

    Viswanathan, Arun

    2012-01-01

    This report describes the results of research into the effects of environment-induced noise on the evaluation process for anomaly detectors in the cyber security domain. This research was conducted during a 10-week summer internship program from the 19th of August, 2012 to the 23rd of August, 2012 at the Jet Propulsion Laboratory in Pasadena, California. The research performed lies within the larger context of the Los Angeles Department of Water and Power (LADWP) Smart Grid cyber security project, a Department of Energy (DoE) funded effort involving the Jet Propulsion Laboratory, California Institute of Technology and the University of Southern California/ Information Sciences Institute. The results of the present effort constitute an important contribution towards building more rigorous evaluation paradigms for anomaly-based intrusion detectors in complex cyber physical systems such as the Smart Grid. Anomaly detection is a key strategy for cyber intrusion detection and operates by identifying deviations from profiles of nominal behavior and are thus conceptually appealing for detecting "novel" attacks. Evaluating the performance of such a detector requires assessing: (a) how well it captures the model of nominal behavior, and (b) how well it detects attacks (deviations from normality). Current evaluation methods produce results that give insufficient insight into the operation of a detector, inevitably resulting in a significantly poor characterization of a detectors performance. In this work, we first describe a preliminary taxonomy of key evaluation constructs that are necessary for establishing rigor in the evaluation regime of an anomaly detector. We then focus on clarifying the impact of the operational environment on the manifestation of attacks in monitored data. We show how dynamic and evolving environments can introduce high variability into the data stream perturbing detector performance. Prior research has focused on understanding the impact of this

  3. Abstracting audit data for lightweight intrusion detection

    KAUST Repository

    Wang, Wei

    2010-01-01

    High speed of processing massive audit data is crucial for an anomaly Intrusion Detection System (IDS) to achieve real-time performance during the detection. Abstracting audit data is a potential solution to improve the efficiency of data processing. In this work, we propose two strategies of data abstraction in order to build a lightweight detection model. The first strategy is exemplar extraction and the second is attribute abstraction. Two clustering algorithms, Affinity Propagation (AP) as well as traditional k-means, are employed to extract the exemplars, and Principal Component Analysis (PCA) is employed to abstract important attributes (a.k.a. features) from the audit data. Real HTTP traffic data collected in our institute as well as KDD 1999 data are used to validate the two strategies of data abstraction. The extensive test results show that the process of exemplar extraction significantly improves the detection efficiency and has a better detection performance than PCA in data abstraction. © 2010 Springer-Verlag.

  4. KUROSHIO INTRUSION INTO THE SOUTH CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-hua; FAN Hai-mei; QU Yuan-yuan

    2006-01-01

    In this article, the circulation of the South China Sea (SCS), which is idealized as the rectangular basin with constant depth, is studied under Kuroshio boundary forces. Starting from the linearly quasi-geostrophic vorticity equation, the solution of the SCS circulation is given in the form of corrected Fourier series under proper boundary conditions. The results show that the intruded current flows westward and separates into the northward branch and the southward branch before arriving at the western boundary. The southward branch flows out of the SCS through the southwestern passage, at the same time, the induced cyclonic (anti-clockwise) ring almost occupies the middle and southern parts, and concomitant anti-cyclonic (clockwise) vortex appears between the cyclone and the western boundary. While the northward branch outflows through the northeastern passage, the anti-cyclonic (clockwise) ring is triggered at the northern part of the SCS. The above two vortexes are both intensified if the south-entering and the north-leaving current loop intrusion are superposed. The outer flow of the northern vortex flows westward, then northward, and then eastward, and it is very similar to the configuration of the SCS Warm Current (SCSWC) at the northern part of the SCS, thus, a kind of generating mechanism of the SCSWC is presented.

  5. Hydraulic barrier against seawater intrusion in the main aquifer of Delta del Llobregat; Barrera hidraulica contra la intrusion marina en el acuifero principal del Delta del Llobregat

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno Gobern, F.; Ninerola Pla, J. M.; Fraile, J.; Juarez, I.; Molinero Huguet, J.; Arcos, D.; Pitarch, J. L.

    2009-07-01

    The main aquifer of Delta del Llobregat (Barcelona, Spain) is affected by seawater intrusion from 1970. For stopping its advance, the Catalan Water Agency is carrying out the construction of a positive hydraulic barrier through the injection of water in 14 wells. This is the first project of these characteristic that it is carried out in Spain and pioneer in Europe. The barrier elevates the groundwater level of the aquifer near the coast and avoids that the seawater penetrates inland, using reclaimed water of Baix Llobregat WWTP with several treatments. The first phase brings already more than 2 years of functioning, with highly positive results since a substantial improvement of the quality of the groundwater has been observed. The second phase is at present under construction. (Author)

  6. Managed Aquifer Recharge (MAR) and Design and Construction of Hydraulic Barriers against Seawater Intrusion: the California Case

    Energy Technology Data Exchange (ETDEWEB)

    Foreman, T. L.

    2014-10-01

    Managed aquifer recharge (MAR) has been practiced in California for over a century, using a range of artificial recharge methods, including surface spreading basins, injection wells and aquifer storage and recovery (ASR) wells. Intense municipal and industrial development of coastal regions, particularly in southern California, during and following World War II, led to overdraft of coastal groundwater basins, where groundwater levels were drawn down below sea level, resulting in seawater intrusion into freshwater aquifers. Surface water is imported from the Colorado River and later northern California to satisfy water demands of a growing population. This imported water is also a water supply used for injection into to injection wells constructed in the 1960s along the coastline to repel seawater from intruding into coastal aquifers. Since the 1960s, these seawater intrusion barriers have evolved in terms of water supplied for injection and in their construction and operation details. Imported water supplies are being completely replaced with highly treated wastewater and the injection wells are being constructed so that they are more automated to reduce operational costs. The West Coast Basin of southern California is provided as a case study of the evolution of hydraulic barriers used for protection against seawater intrusion into coastal aquifers. (Author)

  7. Intrusion Prevention/Intrusion Detection System (IPS/IDS for Wifi Networks

    Directory of Open Access Journals (Sweden)

    Michal Korcak

    2014-07-01

    Full Text Available The nature of wireless networks itself created new vulnerabilities that in the classical wired network s do not exist. This results in an evolutional requireme nt to implement new sophisticated security mechanis m in form of Intrusion Detection and Prevention Systems. This paper deals with security issues of small off ice and home office wireless networks. The goal of our work is to design and evaluate wireless IDPS with u se of packet injection method. Decrease of attacker’s traffic by 95% was observed when compared to attacker’s traffic without deployment of proposed I DPS system.

  8. Effectiveness of Intrusion Prevention Systems (IPS) in Fast Networks

    CERN Document Server

    Shafi, Muhammad Imran; Hayat, Sikandar; Sohail, Imran

    2010-01-01

    Computer systems are facing biggest threat in the form of malicious data which causing denial of service, information theft, financial and credibility loss etc. No defense technique has been proved successful in handling these threats. Intrusion Detection and Prevention Systems (IDPSs) being best of available solutions. These techniques are getting more and more attention. Although Intrusion Prevention Systems (IPSs) show a good level of success in detecting and preventing intrusion attempts to networks, they show a visible deficiency in their performance when they are employed on fast networks. In this paper we have presented a design including quantitative and qualitative methods to identify improvement areas in IPSs. Focus group is used for qualitative analysis and experiment is used for quantitative analysis. This paper also describes how to reduce the responding time for IPS when an intrusion occurs on network, and how can IPS be made to perform its tasks successfully without effecting network speed nega...

  9. Security Enrichment in Intrusion Detection System Using Classifier Ensemble

    Directory of Open Access Journals (Sweden)

    Uma R. Salunkhe

    2017-01-01

    Full Text Available In the era of Internet and with increasing number of people as its end users, a large number of attack categories are introduced daily. Hence, effective detection of various attacks with the help of Intrusion Detection Systems is an emerging trend in research these days. Existing studies show effectiveness of machine learning approaches in handling Intrusion Detection Systems. In this work, we aim to enhance detection rate of Intrusion Detection System by using machine learning technique. We propose a novel classifier ensemble based IDS that is constructed using hybrid approach which combines data level and feature level approach. Classifier ensembles combine the opinions of different experts and improve the intrusion detection rate. Experimental results show the improved detection rates of our system compared to reference technique.

  10. Probabilistic risk assessment for six vapour intrusion algorithms

    NARCIS (Netherlands)

    Provoost, J.; Reijnders, L.; Bronders, J.; Van Keer, I.; Govaerts, S.

    2014-01-01

    A probabilistic assessment with sensitivity analysis using Monte Carlo simulation for six vapour intrusion algorithms, used in various regulatory frameworks for contaminated land management, is presented here. In addition a deterministic approach with default parameter sets is evaluated against obse

  11. Probabilistic risk assessment for six vapour intrusion algorithms

    NARCIS (Netherlands)

    Provoost, J.; Reijnders, L.; Bronders, J.; Van Keer, I.; Govaerts, S.

    2014-01-01

    A probabilistic assessment with sensitivity analysis using Monte Carlo simulation for six vapour intrusion algorithms, used in various regulatory frameworks for contaminated land management, is presented here. In addition a deterministic approach with default parameter sets is evaluated against

  12. SVM Intrusion Detection Model Based on Compressed Sampling

    Directory of Open Access Journals (Sweden)

    Shanxiong Chen

    2016-01-01

    Full Text Available Intrusion detection needs to deal with a large amount of data; particularly, the technology of network intrusion detection has to detect all of network data. Massive data processing is the bottleneck of network software and hardware equipment in intrusion detection. If we can reduce the data dimension in the stage of data sampling and directly obtain the feature information of network data, efficiency of detection can be improved greatly. In the paper, we present a SVM intrusion detection model based on compressive sampling. We use compressed sampling method in the compressed sensing theory to implement feature compression for network data flow so that we can gain refined sparse representation. After that SVM is used to classify the compression results. This method can realize detection of network anomaly behavior quickly without reducing the classification accuracy.

  13. Vapor Intrusion Facility Boundaries - Approximate Extent of Contamination

    Data.gov (United States)

    U.S. Environmental Protection Agency — Theses polygons represent the approximate extent of contamination for Vapor Intrusion facilities. Polygons for non-Federal Facility sites were updated in January,...

  14. An expert system application for network intrusion detection

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, K.A.; Dubois, D.H.; Stallings, C.A.

    1991-01-01

    The paper describes the design of a prototype intrusion detection system for the Los Alamos National Laboratory's Integrated Computing Network (ICN). The Network Anomaly Detection and Intrusion Reporter (NADIR) differs in one respect from most intrusion detection systems. It tries to address the intrusion detection problem on a network, as opposed to a single operating system. NADIR design intent was to copy and improve the audit record review activities normally done by security auditors. We wished to replace the manual review of audit logs with a near realtime expert system. NADIR compares network activity, as summarized in user profiles, against expert rules that define network security policy, improper or suspicious network activities, and normal network and user activity. When it detects deviant (anomalous) behavior, NADIR alerts operators in near realtime, and provides tools to aid in the investigation of the anomalous event. 15 refs., 2 figs.

  15. Probabilistic risk assessment for six vapour intrusion algorithms

    NARCIS (Netherlands)

    Provoost, J.; Reijnders, L.; Bronders, J.; Van Keer, I.; Govaerts, S.

    2014-01-01

    A probabilistic assessment with sensitivity analysis using Monte Carlo simulation for six vapour intrusion algorithms, used in various regulatory frameworks for contaminated land management, is presented here. In addition a deterministic approach with default parameter sets is evaluated against obse

  16. Novel Non-Intrusive Vibration Monitoring System for Turbopumps Project

    Data.gov (United States)

    National Aeronautics and Space Administration — AI Signal Research, Inc. proposes to develop a Non-Intrusive Vibration Measurement System (NI-VMS) for turbopumps which will provide effective on-board/off-board...

  17. Novel Non-Intrusive Vibration Monitoring System for Turbopumps Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ASRI proposes to develop an advanced and commercially viable Non-Intrusive Vibration Monitoring System (NI-VMS) which can provide effective on-line/off-line engine...

  18. Combining Naive Bayes and Decision Tree for Adaptive Intrusion Detection

    CERN Document Server

    Farid, Dewan Md; Rahman, Mohammad Zahidur; 10.5121/ijnsa.2010.2202

    2010-01-01

    In this paper, a new learning algorithm for adaptive network intrusion detection using naive Bayesian classifier and decision tree is presented, which performs balance detections and keeps false positives at acceptable level for different types of network attacks, and eliminates redundant attributes as well as contradictory examples from training data that make the detection model complex. The proposed algorithm also addresses some difficulties of data mining such as handling continuous attribute, dealing with missing attribute values, and reducing noise in training data. Due to the large volumes of security audit data as well as the complex and dynamic properties of intrusion behaviours, several data miningbased intrusion detection techniques have been applied to network-based traffic data and host-based data in the last decades. However, there remain various issues needed to be examined towards current intrusion detection systems (IDS). We tested the performance of our proposed algorithm with existing learn...

  19. Exposure assessment modeling for volatiles--towards an Australian indoor vapor intrusion model.

    Science.gov (United States)

    Turczynowicz, Leonid; Robinson, Neville I

    2007-10-01

    Human health risk assessment of sites contaminated by volatile hydrocarbons involves site-specific evaluations of soil or groundwater contaminants and development of Australian soil health-based investigation levels (HILs). Exposure assessment of vapors arising from subsurface sources includes the use of overseas-derived commercial models to predict indoor air concentrations. These indoor vapor intrusion models commonly consider steady-state assumptions, infinite sources, limited soil biodegradation, negligible free phase, and equilibrium partitioning into air and water phases to represent advective and diffusive processes. Regional model construct influences and input parameters affect model predictions while steady-state assumptions introduce conservatism and jointly highlight the need for Australian-specific indoor vapor intrusion assessment. An Australian non-steady-state indoor vapor intrusion model has been developed to determine cumulative indoor human doses (CIHDs) and to address these concerns by incorporating Australian experimental field data to consider mixing, dilution, ventilation, sink effects and first-order soil and air degradation. It was used to develop provisional HILs for benzene, toluene, ethylbenzene, and xylene (BTEX), naphthalene, and volatile aliphatic and aromatic total petroleum hydrocarbons (TPH) < or = EC16 fractions for crawl space dwellings. This article summarizes current state of knowledge and discusses proposed research for differing exposure scenarios based on Australian dwelling and subsurface influences, concurrent with sensitivity analyses of input parameters and in-field model validation.

  20. A Study on Saltwater Intrusion Around Kolleru Lake, Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    K.Harikrishna

    2012-07-01

    Full Text Available Kolleru Lake, the largest natural fresh water lake in Andhra Pradesh in India, located between Krishna and Godavari deltas is acting as a natural flood balancing reservoir and is fed directly by water from the seasonal rivers Budameru, Ramileru and Tammileru, and is also connected to the Krishna and Godavari drainage system consists of over 68 inflowing drains and channels. Over-exploitation of groundwater and land use conversions to aqua-culture are becoming the sources for salt-water intrusion to this lake and coastal aquifers, in specific, are highly vulnerable to seawater intrusion. Hydrogeomorphological study indicates that the potential aquifers around the Kolleru lake are paleo beach ridges and buried river courses. All other geomorphic features either aquiclude or aquitards are may not be considered as prospective zones for groundwater. Though there are number of open wells present in the villages used for potable water earlier, people switched over to imported water as their drinking water source may be due to significant contaminationof groundwater resources. Present land use activities like aqua-culture, agriculture, large-scale industries and allied industries in and around the Kolleru lake region has large contribution for the change of water quality. The paleo beach ridge areas, where the permeability of the sandy soil is very high, are also converted into aqua ponds. Integrated study using remote sensing, hydrogeology, hydrochemistry and geophysical investigations revealed the extent of salt-water intrusion up to the northern part of the lake which is about 40 km from the coast line. The electrical resistivity of aquifers is less than 1.0 (ohm-m having salinity of more than 1.2 ppt and the resistivity is around 20 (ohm-m where the salinity is less than 0.5 ppt, has also served as an excellent criteria for delineating the fresh-water and salt-water interface. Lenses of fresh water/ brackish water are noticed only in the beach

  1. Forced-folding by laccolith and saucer-shaped sill intrusions on the Earth, planets and icy satellites

    Science.gov (United States)

    Michaut, Chloé

    2017-04-01

    Horizontal intrusions probably initially start as cracks, with negligible surface deformation. Once their horizontal extents become large enough compared to their depths, they make room for themselves by lifting up their overlying roofs, creating characteristic surface deformations that can be observed at the surface of planets. We present a model where magma flows below a thin elastic overlying layer characterized by a flexural wavelength Λ and study the dynamics and morphology of such a magmatic intrusion. Our results show that, depending on its size, the intrusion present different shapes and thickness-to-radius relationships. During a first phase, elastic bending of the overlying layer is the main source of driving pressure in the flow; the pressure decreases as the flow radius increases, the intrusion is bell-shaped and its thickness is close to being proportional to its radius. When the intrusion radius becomes larger than 4 times Λ, the flow enters a gravity current regime and progressively develops a pancake shape with a flat top. We study the effect of topography on flow spreading in particular in the case where the flow is constrained by a lithostatic barrier within a depression, such as an impact crater on planets or a caldera on Earth. We show that the resulting shape for the flow depends on the ratio between the flexural wavelength of the layer overlying the intrusion and the depression radius. The model is tested against terrestrial data and is shown to well explain the size and morphology of laccoliths and saucer-shaped sills on Earth. We use our results to detect and characterize shallow solidified magma reservoirs in the crust of terrestrial planets and potential shallow water reservoirs in the ice shell of icy satellites.

  2. Environmental data processor of the adaptive intrusion data system

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, M.S.

    1977-06-01

    A data acquisition system oriented specifically toward collection and processing of various meteorological and environmental parameters has been designed around a National Semiconductor IMP-16 microprocessor, This system, called the Environmental Data Processor (EDP), was developed specifically for use with the Adaptive Intrusion Data System (AIDS) in a perimeter intrusion alarm evaluation, although its design is sufficiently general to permit use elsewhere. This report describes in general detail the design of the EDP and its interaction with other AIDS components.

  3. A Subset Feature Elimination Mechanism for Intrusion Detection System

    OpenAIRE

    Herve Nkiama; Syed Zainudeen Mohd Said; Muhammad Saidu

    2016-01-01

    several studies have suggested that by selecting relevant features for intrusion detection system, it is possible to considerably improve the detection accuracy and performance of the detection engine. Nowadays with the emergence of new technologies such as Cloud Computing or Big Data, large amount of network traffic are generated and the intrusion detection system must dynamically collected and analyzed the data produce by the incoming traffic. However in a large dataset not all features con...

  4. Enhancing BATTLEMIND: Preventing PTSD by Coping with Intrusive Thoughts

    Science.gov (United States)

    2013-05-01

    replace it right away. This thought replacing skill is especially good to use late at night if you are having trouble sleeping . But, you will need to...then this is a good skill for you to practice with at home so that you can learn to be decent toward yourself. When you spend your time and energy...about intrusive thoughts ◦ CONTROL: traditional CBT skills for coping ◦ RESET: Mindfulness-based skills for coping Thoughts on intrusive thoughts

  5. Biochemical and Clinical Assessments of Segmental Maxillary Posterior Tooth Intrusion

    Science.gov (United States)

    Tasanapanont, Jintana; Wattanachai, Tanapan; Apisariyakul, Janya; Pothacharoen, Peraphan; Kongtawelert, Prachya; Midtbø, Marit

    2017-01-01

    Objective. To compare chondroitin sulphate (CS) levels around maxillary second premolars, first molars, and second molars between the unloaded and the loaded periods and to measure the rates of intrusion of maxillary posterior teeth during segmental posterior tooth intrusion. Materials and Methods. In this prospective clinical study, 105 teeth (from 15 patients exhibiting anterior open bite and requiring maxillary posterior tooth intrusion) were studied. Competitive ELISA was used to detect CS levels. Dental casts (during the unloaded and loaded periods) were scanned, and posterior tooth intrusion distances were measured. Results. During the unloaded period, the median CS levels around maxillary second premolars, first molars, second molars (experimental teeth), and mandibular first molars (negative control) were 0.006, 0.055, 0.056, and 0.012 and during the loaded period were 2.592, 5.738, 4.727, and 0.163 ng/μg of total protein, respectively. The median CS levels around experimental teeth were significantly elevated during the loaded period. The mean rates of maxillary second premolar and first and second molar intrusion were 0.72, 0.58, and 0.40 mm/12 weeks, respectively. Conclusions. Biochemical and clinical assessments suggested that the segmental posterior tooth intrusion treatment modality with 50 g of vertical force per side was sufficient. Trial Registration. The study is registered as TCTR20170206006. PMID:28321256

  6. Combining Naive Bayes and Decision Tree for Adaptive Intrusion Detection

    Directory of Open Access Journals (Sweden)

    Dewan Md. Farid

    2010-04-01

    Full Text Available In this paper, a new learning algorithm for adaptive network intrusion detection using naive Bayesian classifier and decision tree is presented, which performs balance detections and keeps false positives at acceptable level for different types of network attacks, and eliminates redundant attributes as well as contradictory examples from training data that make the detection model complex. The proposedalgorithm also addresses some difficulties of data mining such as handling continuous attribute, dealing with missing attribute values, and reducing noise in training data. Due to the large volumes of security audit data as well as the complex and dynamic properties of intrusion behaviours, several data miningbased intrusion detection techniques have been applied to network-based traffic data and host-based data in the last decades. However, there remain various issues needed to be examined towards current intrusion detection systems (IDS. We tested the performance of our proposed algorithm with existing learning algorithms by employing on the KDD99 benchmark intrusion detection dataset. The experimental results prove that the proposed algorithm achieved high detection rates (DR andsignificant reduce false positives (FP for different types of network intrusions using limited computational resources

  7. The effects of nicotine on intrusive memories in nonsmokers.

    Science.gov (United States)

    Hawkins, Kirsten A; Cougle, Jesse R

    2013-12-01

    Correlational research suggests that smoking increases risk of posttraumatic stress disorder (PTSD), though such research by nature cannot rule out third variable explanations for this relationship. The present study used an analogue trauma film design to experimentally test the effects of nicotine on the occurrence of intrusive memories. Fifty-four healthy nonsmokers were randomly assigned to ingest either a nicotine or placebo lozenge before viewing a film depicting motor vehicle accidents. Participants recorded intrusive memories immediately after the film and for a week via diary. Participants in the nicotine condition reported significantly more intrusive memories immediately after watching the film, yet no group differences emerged on intrusions or intrusion-related distress reported during the following week. Among participants low in dispositional rumination, those who had ingested a nicotine lozenge reported more intrusions in the subsequent week than those in the placebo condition. These findings provide novel experimental evidence for the role of nicotine in increasing risk of PTSD and suggest that nicotine may contribute to trauma-related rumination but not heightened reactivity to trauma cues.

  8. Three Dimensional Vapor Intrusion Modeling: Model Validation and Uncertainty Analysis

    Science.gov (United States)

    Akbariyeh, S.; Patterson, B.; Rakoczy, A.; Li, Y.

    2013-12-01

    Volatile organic chemicals (VOCs), such as chlorinated solvents and petroleum hydrocarbons, are prevalent groundwater contaminants due to their improper disposal and accidental spillage. In addition to contaminating groundwater, VOCs may partition into the overlying vadose zone and enter buildings through gaps and cracks in foundation slabs or basement walls, a process termed vapor intrusion. Vapor intrusion of VOCs has been recognized as a detrimental source for human exposures to potential carcinogenic or toxic compounds. The simulation of vapor intrusion from a subsurface source has been the focus of many studies to better understand the process and guide field investigation. While multiple analytical and numerical models were developed to simulate the vapor intrusion process, detailed validation of these models against well controlled experiments is still lacking, due to the complexity and uncertainties associated with site characterization and soil gas flux and indoor air concentration measurement. In this work, we present an effort to validate a three-dimensional vapor intrusion model based on a well-controlled experimental quantification of the vapor intrusion pathways into a slab-on-ground building under varying environmental conditions. Finally, a probabilistic approach based on Monte Carlo simulations is implemented to determine the probability distribution of indoor air concentration based on the most uncertain input parameters.

  9. Towards Multi-Stage Intrusion Detection using IP Flow Records

    Directory of Open Access Journals (Sweden)

    Muhammad Fahad Umer

    2016-10-01

    Full Text Available Traditional network-based intrusion detection sys-tems using deep packet inspection are not feasible for modern high-speed networks due to slow processing and inability to read encrypted packet content. As an alternative to packet-based intrusion detection, researchers have focused on flow-based intrusion detection techniques. Flow-based intrusion detection systems analyze IP flow records for attack detection. IP flow records contain summarized traffic information. However, flow data is very large in high-speed networks and cannot be processed in real-time by the intrusion detection system. In this paper, an efficient multi-stage model for intrusion detection using IP flows records is proposed. The first stage in the model classifies the traffic as normal or malicious. The malicious flows are further analyzed by a second stage. The second stage associates an attack type with malicious IP flows. The proposed multi-stage model is efficient because the majority of IP flows are discarded in the first stage and only malicious flows are examined in detail. We also describe the implementation of our model using machine learning techniques.

  10. Groundwater salinity in a floodplain forest impacted by saltwater intrusion.

    Science.gov (United States)

    Kaplan, David A; Muñoz-Carpena, Rafael

    2014-11-15

    Coastal wetlands occupy a delicate position at the intersection of fresh and saline waters. Changing climate and watershed hydrology can lead to saltwater intrusion into historically freshwater systems, causing plant mortality and loss of freshwater habitat. Understanding the hydrological functioning of tidally influenced floodplain forests is essential for advancing ecosystem protection and restoration goals, however finding direct relationships between hydrological inputs and floodplain hydrology is complicated by interactions between surface water, groundwater, and atmospheric fluxes in variably saturated soils with heterogeneous vegetation and topography. Thus, an alternative method for identifying common trends and causal factors is required. Dynamic factor analysis (DFA), a time series dimension reduction technique, models temporal variation in observed data as linear combinations of common trends, which represent unexplained common variability, and explanatory variables. DFA was applied to model shallow groundwater salinity in the forested floodplain wetlands of the Loxahatchee River (Florida, USA), where altered watershed hydrology has led to changing hydroperiod and salinity regimes and undesired vegetative changes. Long-term, high-resolution groundwater salinity datasets revealed dynamics over seasonal and yearly time periods as well as over tidal cycles and storm events. DFA identified shared trends among salinity time series and a full dynamic factor model simulated observed series well (overall coefficient of efficiency, Ceff=0.85; 0.52≤Ceff≤0.99). A reduced multilinear model based solely on explanatory variables identified in the DFA had fair to good results (Ceff=0.58; 0.38≤Ceff≤0.75) and may be used to assess the effects of restoration and management scenarios on shallow groundwater salinity in the Loxahatchee River floodplain.

  11. Non-Intrusive Battery Health Monitoring

    Directory of Open Access Journals (Sweden)

    Gajewski Laurent

    2017-01-01

    Full Text Available The “Non-intrusive battery health monitoring”, developed by Airbus Defence and Space (ADS in cooperation with the CIRIMAT-CNRS laboratory and supported by CNES, aims at providing a diagnosis of the battery ageing in flight, called State of Health (SOH, using only the post-treatment of the battery telemetries. The battery current and voltage telemetries are used by a signal processing tool on ground to characterize and to model the battery at low frequencies which allows monitoring the evolution of its degradation with great accuracy. The frequential behaviour estimation is based on inherent disturbances on the current during the nominal functioning of the battery. For instance, on-board thermal control or equipment consumption generates random disturbances on battery current around an average current. The battery voltage response to these current random disturbances enables to model the low frequency impedance of the battery by a signal processing tool. The re-created impedance is then compared with the evolution model of the low frequencies impedance as a function of the battery ageing to estimate accurately battery degradation. Hence, this method could be applied to satellites which are already in orbit and whose battery telemetries acquisition system fulfils the constraints determined in the study. This innovative method is an improvement of present state-of-the-art and is important to have a more accurate in-flight knowledge of battery ageing which is crucial for mission and operation planning and also for possible satellite mission extension or deorbitation. This method is patented by Airbus Defence and Space and CNES.

  12. A Fiber-Optical Intrusion Alarm System Based on Quasi-Distributed Fiber Bragg Grating Sensors

    Institute of Scientific and Technical Information of China (English)

    Qi Jiang; Yun-Jiang Rao; De-Hong Zeng

    2008-01-01

    A fiber-optical intrusion alarm system based on quasi-distributed fiber Bragg grating (FBG) sensors is demonstrated in this paper. The algorithms of empirical mode decomposition (EMD) and wavelet packet characteristic entropy are adopted to determine the intrusion location. The intrusion alarm software based on the Labview is developed, and it is also proved by the experiments. The results show that such a fiber-optical intrusion alarm system can offer the automatic intrusion alarm in real-time.

  13. Intrusion of incisors in adult patients with marginal bone loss.

    Science.gov (United States)

    Melsen, B; Agerbaek, N; Markenstam, G

    1989-09-01

    Elongated and spaced incisors are common problems in patients suffering from severe periodontal disease. Thirty patients characterized by marginal bone loss and deep overbite were treated by intrusion of incisors. Three different methods for intrusion were applied: (1) J hooks and extraoral high-pull headgear, (2) utility arches, (3) intrusion bent into a loop in a 0.17 x 0.25-inch wire, and (4) base arch as described by Burstone. The intrusion was evaluated from the displacement of the apex, incision, and the center of resistance of the most prominent or elongated central incisor. Change in the marginal bone level and the amount of root resorption were evaluated on standardized intraoral radiographs. The pockets were assessed by standardized probing and the clinical crown length was measured on study casts. The results showed that the true intrusion of the center of resistance varied from 0 to 3.5 mm and was most pronounced when intrusion was performed with a base arch. The clinical crown length was generally reduced by 0.5 to 1.0 mm. The marginal bone level approached the cementoenamel junction in all but six cases. All cases demonstrated root resorption varying from 1 to 3 mm. The total amount of alveolar support--that is, the calculated area of the alveolar wall--was unaltered or increased in 19 of the 30 cases. The dependency of the results on the oral hygiene, the force distribution, and the perioral function was evaluated in relation to the individual cases. It was obvious that intrusion was best performed when (1) forces were low (5 to 15 gm per tooth) with the line of action of the force passing through or close to the center of resistance, (2) the gingiva status was healthy, and (3) no interference with perioral function was present.

  14. Management of aquifer recharge in Lebanon by removing seawater intrusion from coastal aquifers.

    Science.gov (United States)

    Masciopinto, Costantino

    2013-11-30

    This study investigates the feasibility of management of aquifer recharge (MAR) in Lebanon by designing well barriers to remove seawater intrusion from the fractured carbonate aquifers. Groundwater flow and saltwater/freshwater 50% sharp interface have been modeled along the coastal area using the Ghyben-Herzberg theory. The groundwater flow simulations have been supported by field transmissivity estimations and depth measurements carried out on 44 wells during 2003. Results have shown the seawater intrusion in coastal aquifers at Jieh and Damour regions. Three well-injection barriers have been proposed. The water volumes for recharge and the barrier positions have been defined by means of groundwater flow simulations. MAR can provide a valuable contribution to colloid (even pathogen) removal from injectant water, although during water infiltration in subsoil the reduction of aquifer permeability causes clogging. A simple new model for estimating the soil-rock permeability reduction due to the well clogging has been presented. The MAR, including the soil aquifer treatment at Damour and Jieh regions, has been studied by considering aquifer transmissivity (and soil porosity) reduction caused by clogging. Furthermore, the appropriate mixing of the injectant water by using reclaimed water, groundwater and surface water can be simulated using the proposed models. The time required to achieve 5% of rock permeability reduction at the proposed well barriers ranged from 71 to 935 d, by changing water quality and flow rate for recharge. This study can assist regional governments with water management in areas affected by scarcity of freshwater by implementing appropriate well-barrier projects.

  15. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  16. Influences of Three Gorges Reservoir on salt water intrusion from the north branch to the south branch of the Yangtze River estuary%三峡水库对长江河口北支咸潮倒灌影响探讨

    Institute of Scientific and Technical Information of China (English)

    唐建华; 赵升伟; 刘玮祎; 陶静; 缪世强

    2011-01-01

    To investigate the influence of the operation of the Three Gorges Reservoir (TGR) on the salt water intrusion (SWI) from the North Branch (NB) to the South Branch (SB) of the Yangtze River estuary (YRE) , a study was conducted by analyzing salinity observations before and after the TGR operation. The results indicate that SWI from the NB of the YRE started earlier in a typical year; the intensity of SWI increased from October to November, while it reduced from December to April of the next year due to the operation of the TGR; the reduction rate of the intensity of SWI is much less than the increasing rate; during the period from January to April when SWI is the most serious and the intake of fresh water from the YRE is the most important, the reduction of SWI is not great enough, so the effect of the operation of the TGR is not significant during this period; the operation of the TGR has little effect on the reduction of SWI of the whole year, but it has reduced the intensity of the most serious SWI from the NB to SB, which can contribute to the safety of the supply of freshwater in the YRE area.%为了解三峡水库的运行对长江河口北支咸潮倒灌的影响,对三峡水库初步运行前后北支咸潮倒灌的变化进行了分析.结果表明:三峡水库运行后,受水库下泄水量变化影响,北支咸潮倒灌时间提前,10~11月成潮倒灌强度增加,12月至次年4月倒灌强度减弱,咸潮倒灌强度的降幅小于增幅;在咸潮倒灌最为严重和长江口淡水利用最为重要的1-4月,水库的实际运行所引起的北支咸潮倒灌减弱的幅度并不大;三峡水库的实际运行使得北支成潮倒灌的强度在各月重新分配,但对一年中整个咸潮期咸潮倒灌的总强度影响不大;水库运行后,北支极端咸潮倒灌的强度降低,这对提高长江口水源地的供水安全及保证率有利.

  17. Testing alternative conceptual models of seawater intrusion in a coastal aquifer using computer simulation, southern California, USA

    Science.gov (United States)

    Nishikawa, T.

    1997-01-01

    Two alternative conceptual models of the physical processes controlling seawater intrusion in a coastal basin in California, USA, were tested to identify a likely principal pathway for seawater intrusion. The conceptual models were tested by using a two-dimensional, finite-element groundwater flow and transport model. This pathway was identified by the conceptual model that best replicated the historical data. The numerical model was applied in cross section to a submarine canyon that is a main avenue for seawater to enter the aquifer system underlying the study area. Both models are characterized by a heterogeneous, layered, water-bearing aquifer. However, the first model is characterized by flat-lying aquifer layers and by a high value of hydraulic conductivity in the basal aquifer layer, which is thought to be a principal conduit for seawater intrusion. The second model is characterized by offshore folding, which was modeled as a very nearshore outcrop, thereby providing a shorter path for seawater to intrude. General conclusions are that: 1) the aquifer system is best modeled as a flat, heterogeneous, layered system; 2) relatively thin basal layers with relatively high values of hydraulic conductivity are the principal pathways for seawater intrusion; and 3) continuous clay layers of low hydraulic conductivity play an important role in controlling the movement of seawater.

  18. How Saccade Intrusions Affect Subsequent Motor and Oculomotor Actions

    Science.gov (United States)

    Terao, Yasuo; Fukuda, Hideki; Tokushige, Shin-ichi; Inomata-Terada, Satomi; Ugawa, Yoshikazu

    2017-01-01

    In daily activities, there is a close spatial and temporal coupling between eye and hand movements that enables human beings to perform actions smoothly and accurately. If this coupling is disrupted by inadvertent saccade intrusions, subsequent motor actions suffer from delays, and lack of coordination. To examine how saccade intrusions affect subsequent voluntary actions, we used two tasks that require subjects to make motor/oculomotor actions in response to a visual cue. One was the memory guided saccade (MGS) task, and the other the hand reaction time (RT) task. The MGS task required subjects to initiate a voluntary saccade to a memorized target location, which is indicated shortly before by a briefly presented cue. The RT task required subjects to release a button on detection of a visual target, while foveating on a central fixation point. In normal subjects of various ages, inadvertent saccade intrusions delayed subsequent voluntary motor, and oculomotor actions. We also studied patients with Parkinson's disease (PD), who are impaired not only in initiating voluntary saccades but also in suppressing unwanted reflexive saccades. Saccade intrusions also delayed hand RT in PD patients. However, MGS was affected by the saccade intrusion differently. Saccade intrusion did not delay MGS latency in PD patients who could perform MGS with a relatively normal latency. In contrast, in PD patients who were unable to initiate MGS within the normal time range, we observed slightly decreased MGS latency after saccade intrusions. What explains this paradoxical phenomenon? It is known that motor actions slow down when switching between controlled and automatic behavior. We discuss how the effect of saccade intrusions on subsequent voluntary motor/oculomotor actions may reflect a similar switching cost between automatic and controlled behavior and a cost for switching between different motor effectors. In contrast, PD patients were unable to initiate internally guided MGS in

  19. Non-intrusive characterization methods for wastewater-affected groundwater plumes discharging to an alpine lake.

    Science.gov (United States)

    Roy, James W; Robillard, Jasen M; Watson, Susan B; Hayashi, Masaki

    2009-02-01

    Streams and lakes in rocky environments are especially susceptible to nutrient loading from wastewater-affected groundwater plumes. However, the use of invasive techniques such as drilling wells, installing piezometers or seepage meters, to detect and characterize these plumes can be prohibitive. In this work, we report on the use of four non-intrusive methods for this purpose at a site in the Rocky Mountains. The methods included non-invasive geophysical surveys of subsurface electrical conductivity (EC), in-situ EC measurement of discharging groundwater at the lake-sediment interface, shoreline water sampling and nutrient analysis, and shoreline periphyton sampling and analysis of biomass and taxa relative abundance. The geophysical surveys were able to detect and delineate two high-EC plumes, with capacitively coupled ERI (OhmMapper) providing detailed two-dimensional images. In situ measurements at the suspected discharge locations confirmed the presence of high-EC water in the two plumes and corroborated their spatial extent. The nutrient and periphyton results showed that only one of the two high-EC plumes posed a current eutrophication threat, with elevated nitrogen and phosphorus levels, high localized periphyton biomass and major shifts in taxonomic composition to taxa that are commonly associated with anthropogenic nutrient loading. This study highlights the need to use non-intrusive methods in combination, with geophysical and water EC-based methods used for initial detection of wastewater-affected groundwater plumes, and nutrient or periphyton sampling used to characterize their ecological effects.

  20. A multi-compartment mass transfer model applied to building vapor intrusion

    Science.gov (United States)

    Murphy, Brian L.; Chan, Wanyu R.

    2011-12-01

    We develop a systematic approach to model steady-state advective and diffusive fluxes, as well as phase changes, between multi-media environmental compartments. The approach results in four simple rules for constructing mass transfer coefficients. Results are analogous to electrical circuit theory with resistors, including variable resistors or potentiometers, in parallel and series. This general approach lends itself particularly well to vapor intrusion calculations where there are multi-media compartments involving groundwater, soil, and air. In addition to showing that the model reduces to the well-known Johnson & Ettinger model in limiting cases, we illustrate its simplicity and ease of use with several examples: (1) an example of how multiple partition coefficients collapse into a single partition coefficient illustrated by a three-phase problem involving tar, water, and air, (2) determination of when the presence of a basement significantly lowers first floor exposures, and (3) addition of diffusion in the saturated zone to the model to investigate whether the resistance associated with this compartment can be neglected. We conclude that if the water table is truly steady, this resistance would be very significant. Therefore, a vapor intrusion model that neglects both water table fluctuations and diffusion in groundwater is ignoring important physical phenomena.

  1. Intrusão dentária utilizando mini-implantes Orthodontic intrusion with mini-implant anchorage

    Directory of Open Access Journals (Sweden)

    Telma Martins de Araújo

    2008-10-01

    Full Text Available INTRODUÇÃO: dentre os diversos tipos de movimentos dentários induzidos ortodonticamente, o de intrusão é, sem dúvida, um dos mais difíceis de serem conseguidos. A mecânica intrusiva convencional, apesar de viável, é complexa, no que diz respeito ao controle de seus efeitos colaterais. Isso, em grande parte, refere-se à dificuldade em se obter uma ancoragem satisfatória. Neste contexto, os mini-implantes, por oferecerem efetiva ancoragem esquelética, têm se mostrado de extrema valia para os ortodontistas, tornando a intrusão, tanto de dentes anteriores quanto posteriores, um procedimento cada vez mais simples, do ponto de vista mecânico. OBJETIVO: pretende-se, então, neste artigo, descrever e demonstrar, clinicamente, as diversas possibilidades de utilização dos mini-implantes como recurso de ancoragem para o movimento de intrusão.INTRODUCTION: Among all different varieties of orthodontically induced tooth movement, intrusion is, without doubt, one of the most difficult movements to be reached. Conventional intrusive biomechanics, although possible, may lead to undesirable side-effects. These events, in most cases, are related to the difficulty in obtaining an efficient anchorage unit. Then, mini-implants, because of their high success rates of effective skeletal anchorage, are valuable devices to orthodontists, transforming the intrusion movement, both at the anterior and the posterior regions, a more and more uncomplicated biomechanical procedure. AIM: to describe and show, clinically, different ways of using mini-implants as an anchorage system to intrusion movement.

  2. Fuzzy Aided Application Layer Semantic Intrusion Detection System - FASIDS

    CERN Document Server

    Sangeetha, S; 10.5121/ijnsa.2010.2204

    2010-01-01

    The objective of this is to develop a Fuzzy aided Application layer Semantic Intrusion Detection System (FASIDS) which works in the application layer of the network stack. FASIDS consist of semantic IDS and Fuzzy based IDS. Rule based IDS looks for the specific pattern which is defined as malicious. A non-intrusive regular pattern can be malicious if it occurs several times with a short time interval. For detecting such malicious activities, FASIDS is proposed in this paper. At application layer, HTTP traffic's header and payload are analyzed for possible intrusion. In the proposed misuse detection module, the semantic intrusion detection system works on the basis of rules that define various application layer misuses that are found in the network. An attack identified by the IDS is based on a corresponding rule in the rule-base. An event that doesn't make a 'hit' on the rule-base is given to a Fuzzy Intrusion Detection System (FIDS) for further analysis.

  3. A HIERARCHICAL INTRUSION DETECTION ARCHITECTURE FOR WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    Hossein Jadidoleslamy

    2011-10-01

    Full Text Available Networks protection against different types of attacks is one of most important posed issue into the network andinformation security application domains. This problem on Wireless Sensor Networks (WSNs, in attention to theirspecial properties, has more importance. Now, there are some of proposed architectures and guide lines to protectWireless Sensor Networks (WSNs against different types of intrusions; but any one of them do not has acomprehensive view to this problem and they are usually designed and implemented in single-purpose; but, theproposed design in this paper tries to has been a comprehensive view to this issue by presenting a complete andcomprehensive Intrusion Detection Architecture (IDA. The main contribution of this architecture is its hierarchicalstructure; i.e., it is designed and applicable, in one or two levels, consistent to the application domain and itsrequired security level. Focus of this paper is on the clustering WSNs, designing and deploying Cluster-basedIntrusion Detection System (CIDS on cluster-heads and Wireless Sensor Network wide level Intrusion DetectionSystem (WSNIDS on the central server. Suppositions of the WSN and Intrusion Detection Architecture (IDA are:static and heterogeneous network, hierarchical and clustering structure, clusters' overlapping and using hierarchicalrouting protocol such as LEACH, but along with minor changes. Finally, the proposed idea has been verified bydesigning a questionnaire, representing it to some (about 50 people experts and then, analyzing and evaluating itsacquired results.

  4. Sensitive Data Protection Based on Intrusion Tolerance in Cloud Computing

    Directory of Open Access Journals (Sweden)

    Jingyu Wang

    2011-02-01

    Full Text Available Service integration and supply on-demand coming from cloud computing can significantly improve the utilization of computing resources and reduce power consumption of per service, and effectively avoid the error of computing resources. However, cloud computing is still facing the problem of intrusion tolerance of the cloud computing platform and sensitive data of new enterprise data center. In order to address the problem of intrusion tolerance of cloud computing platform and sensitive data in new enterprise data center, this paper constructs a virtualization intrusion tolerance system based on cloud computing by researching on the existing virtualization technology, and then presents a method of intrusion tolerance to protect sensitive data in cloud data center based on virtual adversary structure by utilizing secret sharing. This system adopts the method of hybrid fault model, active and passive replicas, state update and transfer, proactive recovery and diversity, and initially implements to tolerate F faulty replicas in N=2F+1 replicas and ensure that only F+1 active replicas to execute during the intrusion-free stage. The remaining replicas are all put into passive mode, which significantly reduces the resource consuming in cloud platform. At last we prove the reconstruction and confidentiality property of sensitive data by utilizing secret sharing.

  5. Perception of the English intrusive stops by Korean listeners

    Science.gov (United States)

    Han, Jeong-Im

    2002-05-01

    This paper reports results of an experiment examining Korean listeners' perception of English intrusive stops in nasal-obstruent clusters. The experiment tests (1) how often intrusive stops are perceived; (2) how language-specific syllable structure constraints influence the perception, given the fact that Korean does not allow consonant clusters in syllable onsets and codas; (3) whether even the perception of phonetic variables like intrusive stops, not phonemes, could be improved by learning. Ninety English non-words with a monosyllable structure of CVC1C2 were created, where C1=/m,n,N/, and C2=/p,k,s/. The stimuli including additional 90 filler items were recorded by three native English speakers and one representative data among them was given to three groups of native Korean listeners in terms of their English proficiency. Each was asked to monitor the target sounds [Warner and Weber, J. Phonetics 29, 23-52 (2001)]. The preliminary results show that identification of intrusive stops in English is totally dependent on Korean syllable structure, so even stimuli with strong acoustic cues were misparsed. Nonetheless, there's a high correlation between perception of intrusive stops and listeners' English proficiency, showing the possibility of the improvement of perception by learning.

  6. Orthodontic intrusive movement to reduce infrabony defects in periodontal pacients

    Directory of Open Access Journals (Sweden)

    Aldrieli Regina Ambrósio

    2008-01-01

    Full Text Available The adult tends to be an excellent orthodontic patient, because he/she is motivated and cooperative. Nevertheless, many adult patientspresent periodontal problems. Intrusive movement is usually necessary against an area with infrabony defects, and in order for treatmentto be successful, it is necessary for all related aspects to be well understood. The aim of this study was to discuss the feasibility and efficacy of orthodontic intrusion as a means of reducing infrabony defects caused by periodontal disease. The methodology used was reviewed in the literature, from which articles were selected using the MEDLINE, LILACS and BBO databases. After periodontal treatment and maintenance with suitable bacterial plaque control has been performed, orthodontic treatment with intrusive tooth movement can be performed in case of pathological tooth migration and extrusion. The segmented arch technique is the most indicated for intruding teeth with infrabony defects because it is capable of developing light and continuous forces. Furthermore, although studies did not confirm, they suggested that orthodontic intrusion could lead to the formation of new periodontal support tissue. With a multidisciplinary approach, it is possible to successfully perform intrusion movements in teeth that present infrabony defects, provided that periodontal inflammation has been treated and the patient presents an excellent level of plaque control. Among the benefits of this approach are: better appearance, better access to dental hygiene, restitution of incisal occlusion and reduction in non axial load.

  7. Distributed intrusion detection for mobile ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    Yi Ping; Jiang Xinghao; Wu Yue; Liu Ning

    2008-01-01

    Mobile ad hoc networking(MANET)has become an exciting and important technology in recent years,because of the rapid proliferation of wireless devices.Mobile ad hoc networks is highly vulnerable to attacks due to the open medium,dynamically changing network topology,cooperative algorithms,and lack of centralized monitoring and management point.The traditional way of protecting networks with firewalls and encryption software is no longer sufficient and effective for those features.A distributed intrusion detection approach based on timed automata is given.A cluster-based detection scheme is presented,where periodically a node is elected as the monitor node for a cluster.These monitor nodes can not only make local intrusion detection decisions,but also cooperatively take part in global intrusion detection.And then the timed automata is constructed by the way of manually abstracting the correct behaviours of the node according to the routing protocol of dynamic source routing(DSR).The monitor nodes can verify the behaviour of every nodes by timed automata,and validly detect real-time attacks without signatures of intrusion or trained data.Compared with the architecture where each node is its own IDS agent,the approach is much more efficient while maintaining the same level of effectiveness.Finally,the intrusion detection method is evaluated through simulation experiments.

  8. Distress and recurrence of intrusive thoughts in younger and older adults.

    Science.gov (United States)

    Magee, Joshua C; Teachman, Bethany A

    2012-03-01

    The current study incorporated a life span perspective into existing theories of intrusive thoughts to examine age-related differences in the difficulty controlling intrusive thoughts, the distress following intrusive thought recurrences, and the meanings assigned to these recurrences. Younger (N = 51) and older (N = 49) community adults were randomly assigned to suppress (i.e., keep out of mind) or monitor an intrusive thought. Participants rated their positive and negative affect throughout engagement with the intrusive thought, and they also rated the meanings they gave to recurrences of their everyday intrusive thoughts. The results demonstrated that older adults tended to perceive greater difficulty with controlling the intrusive thought than younger adults despite the fact that they did not differ in the actual recurrence of the intrusive thought. With regard to distress, older adults experienced steadier levels of positive affect than younger adults throughout engagement with the intrusive thought. However, older adults also reported greater residual negative affect after engaging with the intrusive thought than younger adults. Finally, older and younger adults appeared to assign meanings to recurrences of intrusive thoughts in line with age-relevant concerns. Specifically, older adults were prone to interpret the recurrence of intrusive thoughts as a sign of cognitive decline, but they were less likely than younger adults to see intrusive thoughts as a sign of moral failure. Together, these results highlight a range of potential risk and protective factors in older adults for experiencing emotion dysregulation after intrusive thoughts.

  9. Geology and Geochemistry of Reworking Gold Deposits in Intrusive Rocks of China—Ⅱ Gold Deposits and Their Genesis

    Institute of Scientific and Technical Information of China (English)

    王秀璋; 程景平; 等

    1998-01-01

    Gold deposits in intrusive masses include the veinlet dissemination,quartz vein and veinlet dissemination+vein types,They are distributed in fracture zones along the endocontact zone of a batholith or in the centre and edge of a stock.The metallogenic epochs are Yenshanian,Hercynian,Archean,Proterozoic and Himalayan,The gold deposits are characterized by a big difference in time span between gold mineralization and the formation of host masses Ore-forming materials were derived from the masses and auriferous strata and ore-forming fluids came from meteoric and formation waters.When circulating water was heated by ascending heat flow,gold would be extracted,concentrated and transported from auriferous rocks and then precipitated in the masses during the late tectonic movement,Finally gold deposits were formed in the intrusive masses.

  10. One-Dimensional Unsteady Analytical Solution of Salinity Intrusion in Estuaries

    Institute of Scientific and Technical Information of China (English)

    SONG Zhi-yao; HUANG Xuan-jun; ZHANG Hong-gui; CHEN Xi-qing; KONG Jun

    2008-01-01

    Based on the one-dimensional salinity transport equation with constant diffusion coefficient, and separated water flow velocity into runoff and tidal current with the single-frequency in an idealized estuary, the simplest unsteady analytical solution of salinity intrusion is deduced and the estimation formula of diffusion coefficient is obtained in this paper. The unsteady solution indicates that salinity process in estuaries results from the interaction of runoff and tidal current, and its amplitude is in direct proportion to the product of the velocity of runoff water and the amplitude of tidal flow velocity and in inverse proportion to the diffusion coefficient and the tidal angular frequency, and its phase lag tidal flow with π/2 which reveals the basic features of the maximum salinity appearing after flood slack and the minimum salinity appearing before ebb slack under the effect of runoff (the advance or lag time is relative to the magnitude of runoff and tidal flow). According to the measured flow velocity and salinity data, the salinity diffusion coefficient could be estimated. Finally, with the field data of observing sites on the deepwater navigation channel of the Yangtze Estuary, the diffusion coefficient is calculated and a comparative analysis of simulated and measured of salinity process is made. The results show that the solution can comprehensively reflects the basic characteristics and processes of salinity intrusion under the interaction of runoff and tidal flow in estuaries. The solution is not only suitable for theoretical research, but also convenient for estimating reasonable physical parameters and giving the initial condition in the salinity intrusion numerical simulation.

  11. Why seawater intrusion has not yet occurred in the Kaluvelli-Pondicherry basin, Tamil Nadu, India

    Science.gov (United States)

    Vincent, Aude; Violette, Sophie

    2017-03-01

    Worldwide, coastal aquifers are threatened by seawater intrusion. The threat is greatest when aquifers are overexploited or when recharge is low due to a semi-arid or arid climate. The Kaluvelli-Pondicherry sedimentary basin in Tamil Nadu (India) presents both these characteristics. Groundwater levels in the Vanur aquifer can reach 50 m below sea level at less than 20 km inland. This groundwater depletion is due to an exponential increase in extraction for irrigation over 35 years. No seawater intrusion has yet been detected, but a sulphate-rich mineralization is observed, the result of upward vertical leakage from the underlying Ramanathapuram aquifer. To characterize the mechanisms involved, and to facilitate effective water management, hydrogeological numerical modelling of this multi-layered system has been conducted. Existing and acquired geological and hydrodynamic data have been applied to a quasi-3D hydrogeological model, NEWSAM. Recharge had been previously quantified through the inter-comparison of hydrological models, based on climatological and surface-flow field measurements. Sensitivity tests on parameters and boundary conditions associated with the sea were performed. The resulting water balances for each aquifer led to hypotheses of (1) an offshore fresh groundwater stock, and (2) a reversal and increase of the upward leakage from the Ramanathapuram aquifer, thus corroborating the hypothesis proposed to explain geochemical results of the previous study, and denying a seawater intrusion. Palaeo-climate review supports the existence of favourable hydro-climatological conditions to replenish an offshore groundwater stock of the Vanur aquifer in the past. The extent of this fresh groundwater stock was calculated using the Kooi and Groen method.

  12. Why seawater intrusion has not yet occurred in the Kaluvelli-Pondicherry basin, Tamil Nadu, India

    Science.gov (United States)

    Vincent, Aude; Violette, Sophie

    2017-09-01

    Worldwide, coastal aquifers are threatened by seawater intrusion. The threat is greatest when aquifers are overexploited or when recharge is low due to a semi-arid or arid climate. The Kaluvelli-Pondicherry sedimentary basin in Tamil Nadu (India) presents both these characteristics. Groundwater levels in the Vanur aquifer can reach 50 m below sea level at less than 20 km inland. This groundwater depletion is due to an exponential increase in extraction for irrigation over 35 years. No seawater intrusion has yet been detected, but a sulphate-rich mineralization is observed, the result of upward vertical leakage from the underlying Ramanathapuram aquifer. To characterize the mechanisms involved, and to facilitate effective water management, hydrogeological numerical modelling of this multi-layered system has been conducted. Existing and acquired geological and hydrodynamic data have been applied to a quasi-3D hydrogeological model, NEWSAM. Recharge had been previously quantified through the inter-comparison of hydrological models, based on climatological and surface-flow field measurements. Sensitivity tests on parameters and boundary conditions associated with the sea were performed. The resulting water balances for each aquifer led to hypotheses of (1) an offshore fresh groundwater stock, and (2) a reversal and increase of the upward leakage from the Ramanathapuram aquifer, thus corroborating the hypothesis proposed to explain geochemical results of the previous study, and denying a seawater intrusion. Palaeo-climate review supports the existence of favourable hydro-climatological conditions to replenish an offshore groundwater stock of the Vanur aquifer in the past. The extent of this fresh groundwater stock was calculated using the Kooi and Groen method.

  13. A Cooperative Network Intrusion detection Based on Fuzzy SVMs

    Directory of Open Access Journals (Sweden)

    Shaohua Teng

    2010-04-01

    Full Text Available There is a large number of noise in the data obtained from network, which deteriorates intrusion detection performance. To delete the noise data, data preprocessing is done before the construction of hyperplane in support vector machine (SVM. By introducing fuzzy theory into SVM, a new method is proposed for network intrusion detection.  Because the attack behavior is different for different network protocol, a different fuzzy membership function is formatted, such that for each class of protocol there is a SVM. To implement this approach, a fuzzy SVM-based cooperative network intrusion detection system with multi-agent architecture is presented. It is composed of three types of agents corresponding to TCP, UDP, and ICMP protocols, respectively. Simulation experiments are done by using KDD CUP 1999 data set, results show that the training time is significantly shortened, storage space requirement is reduced, and classification accuracy is improved.

  14. Intrusion detection based on system calls and homogeneous Markov chains

    Institute of Scientific and Technical Information of China (English)

    Tian Xinguang; Duan Miyi; Sun Chunlai; Li Wenfa

    2008-01-01

    A novel method for detecting anomalous program behavior is presented, which is applicable to hostbased intrusion detection systems that monitor system call activities. The method constructs a homogeneous Markov chain model to characterize the normal behavior of a privileged program, and associates the states of the Markov chain with the unique system calls in the training data. At the detection stage, the probabilities that the Markov chain model supports the system call sequences generated by the program are computed. A low probability indicates an anomalous sequence that may result from intrusive activities. Then a decision rule based on the number of anomalous sequences in a locality frame is adopted to classify the program's behavior. The method gives attention to both computational efficiency and detection accuracy, and is especially suitable for on-line detection. It has been applied to practical host-based intrusion detection systems.

  15. CUSUM-Based Intrusion Detection Mechanism for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Bishan Ying

    2014-01-01

    Full Text Available The nature of wireless sensor networks (WSNs makes them very vulnerable to adversary's malicious attacks. Therefore, network security is an important issue to WSNs. Due to the constraints of WSN, intrusion detection in WSNs is a challengeable task. In this paper, we present a novel intrusion detection mechanism for WSNs, which is composed of a secure data communication algorithm and an intrusion detection algorithm. The major contribution of this paper is that we propose an original secure mechanism to defend WSNs against malicious attacks by using the information generated during data communication. The approach is able to protect the data communication in a WSN even if some sensor nodes are compromised by adversary. The proposed approach is easy to be implemented and performed in resource-constrained WSN. We also evaluate the proposed approach by a simulation experiment and analyze the simulation results in detail.

  16. Distributed intrusion detection system based on fuzzy rules

    Science.gov (United States)

    Qiao, Peili; Su, Jie; Liu, Yahui

    2006-04-01

    Computational Intelligence is the theory and method solving problems by simulating the intelligence of human using computer and it is the development of Artificial Intelligence. Fuzzy Technique is one of the most important theories of computational Intelligence. Genetic Fuzzy Technique and Neuro-Fuzzy Technique are the combination of Fuzzy Technique and novel techniques. This paper gives a distributed intrusion detection system based on fuzzy rules that has the characters of distributed parallel processing, self-organization, self-learning and self-adaptation by the using of Neuro-Fuzzy Technique and Genetic Fuzzy Technique. Specially, fuzzy decision technique can be used to reduce false detection. The results of the simulation experiment show that this intrusion detection system model has the characteristics of distributed, error tolerance, dynamic learning, and adaptation. It solves the problem of low identifying rate to new attacks and hidden attacks. The false detection rate is low. This approach is efficient to the distributed intrusion detection.

  17. Hybrid Intrusion Detection and Prediction multiAgent System HIDPAS

    CERN Document Server

    Jemili, Farah; Ahmed, Mohamed Ben

    2009-01-01

    This paper proposes an intrusion detection and prediction system based on uncertain and imprecise inference networks and its implementation. Giving a historic of sessions, it is about proposing a method of supervised learning doubled of a classifier permitting to extract the necessary knowledge in order to identify the presence or not of an intrusion in a session and in the positive case to recognize its type and to predict the possible intrusions that will follow it. The proposed system takes into account the uncertainty and imprecision that can affect the statistical data of the historic. The systematic utilization of an unique probability distribution to represent this type of knowledge supposes a too rich subjective information and risk to be in part arbitrary. One of the first objectives of this work was therefore to permit the consistency between the manner of which we represent information and information which we really dispose.

  18. Intrusion Awareness Based on Data Fusion and SVM Classification

    Directory of Open Access Journals (Sweden)

    Ramnaresh Sharma

    2012-06-01

    Full Text Available Network intrusion awareness is important factor for risk analysis of network security. In the current decade various method and framework are available for intrusion detection and security awareness. Some method based on knowledge discovery process and some framework based on neural network. These entire model take rule based decision for the generation of security alerts. In this paper we proposed a novel method for intrusion awareness using data fusion and SVM classification. Data fusion work on the biases of features gathering of event. Support vector machine is super classifier of data. Here we used SVM for the detection of closed item of ruled based technique. Our proposed method simulate on KDD1999 DARPA data set and get better empirical evaluation result in comparison of rule based technique and neural network model.

  19. Intrusion Awareness Based on Data Fusion and SVM Classification

    Directory of Open Access Journals (Sweden)

    Ramnaresh Sharma

    2012-06-01

    Full Text Available Network intrusion awareness is important factor forrisk analysis of network security. In the currentdecade various method and framework are availablefor intrusion detection and security awareness.Some method based on knowledge discovery processand some framework based on neural network.These entire model take rule based decision for thegeneration of security alerts. In this paper weproposed a novel method for intrusion awarenessusing data fusion and SVM classification. Datafusion work on the biases of features gathering ofevent. Support vector machine is super classifier ofdata. Here we used SVM for the detection of closeditem of ruled based technique. Our proposedmethod simulate on KDD1999 DARPA data set andget better empirical evaluation result in comparisonof rule based technique and neural network model.

  20. HYBRID ARCHITECTURE FOR DISTRIBUTED INTRUSION DETECTION SYSTEM IN WIRELESS NETWORK

    Directory of Open Access Journals (Sweden)

    Seyedeh Yasaman Rashida

    2013-06-01

    Full Text Available In order to the rapid growth of the network application, new kinds of network attacks are emerging endlessly. So it is critical to protect the networks from attackers and the Intrusion detection technology becomes popular. Therefore, it is necessary that this security concern must be articulate right from the beginning of the network design and deployment. The intrusion detection technology is the process of identifying network activity that can lead to a compromise of security policy. Lot of work has been done in detection of intruders. But the solutions are not satisfactory. In this paper, we propose a novel Distributed Intrusion Detection System using Multi Agent In order to decrease false alarms and manage misuse and anomaly detects.

  1. Research of Intrusion Detection Technology and its Formal Modeling

    Directory of Open Access Journals (Sweden)

    PENG Yali

    2009-10-01

    Full Text Available The intrusion detection technology is one of the most important dynamic security technologies, which can be used in the critical security system construction and the basic service protection. Apparently, applying formal specification to the procedure of developing an intrusion detection system can fulfill their security requirement and win the confidence of users of the secured systems. Taking a DDoS intrusion detection system as an example, we establish integrity sub-regular database through analyzing the default characteristics and universal characteristics in communication of DDoS attack, which can guarantee fast and effective detection in each appeared DDoS attack. At the same time, we use the association rules mining algorithm mine new rules and their association pattern to detect the unknown attack, and illustrate how Z can be used to specify and model the security-critical systems.

  2. Alerts Visualization and Clustering in Network-based Intrusion Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dr. Li [University of Tennessee; Gasior, Wade C [ORNL; Dasireddy, Swetha [University of Tennessee

    2010-04-01

    Today's Intrusion detection systems when deployed on a busy network overload the network with huge number of alerts. This behavior of producing too much raw information makes it less effective. We propose a system which takes both raw data and Snort alerts to visualize and analyze possible intrusions in a network. Then we present with two models for the visualization of clustered alerts. Our first model gives the network administrator with the logical topology of the network and detailed information of each node that involves its associated alerts and connections. In the second model, flocking model, presents the network administrator with the visual representation of IDS data in which each alert is represented in different color and the alerts with maximum similarity move together. This gives network administrator with the idea of detecting various of intrusions through visualizing the alert patterns.

  3. Application of Time-Domain Electromagnetic Method in Investigating Saltwater Intrusion of Santiago Island (Cape Verde)

    Science.gov (United States)

    Gonçalves, Rui; Farzamian, Mohammad; Monteiro Santos, Fernando A.; Represas, Patrícia; Mota Gomes, A.; Lobo de Pina, A. F.; Almeida, Eugénio P.

    2017-08-01

    Santiago Island, the biggest and most populated island of the Cape Verde Republic, is characterised by limited surface waters and strong dependence on groundwater sources as the primary source of natural water supply for extensive agricultural activity and human use. However, as a consequence of the scarce precipitation and high evaporation as well as the intense overexploitation of the groundwater resources, the freshwater management is also in a delicate balance with saltwater at coastal areas. The time-domain electromagnetic (TDEM) method is used to locate the extent of saltwater intrusion in four important agricultural regions in Santiago Island; São Domingos, Santa Cruz, São Miguel, and Tarrafal. The application of this method in Santiago Island proves it to be a successful tool in imaging the fresh/saltwater interface location. Depths to the saline zones and extensions of saline water are mapped along eight TDEM profiles.

  4. Power-Aware Intrusion Detection in Mobile Ad Hoc Networks

    Science.gov (United States)

    Şen, Sevil; Clark, John A.; Tapiador, Juan E.

    Mobile ad hoc networks (MANETs) are a highly promising new form of networking. However they are more vulnerable to attacks than wired networks. In addition, conventional intrusion detection systems (IDS) are ineffective and inefficient for highly dynamic and resource-constrained environments. Achieving an effective operational MANET requires tradeoffs to be made between functional and non-functional criteria. In this paper we show how Genetic Programming (GP) together with a Multi-Objective Evolutionary Algorithm (MOEA) can be used to synthesise intrusion detection programs that make optimal tradeoffs between security criteria and the power they consume.

  5. A national inventory of seawater intrusion vulnerability for Australia

    Directory of Open Access Journals (Sweden)

    Leanne K. Morgan

    2015-09-01

    New hydrological insights for the region: The combination of methods identified areas of highest risk to SWI including unconfined aquifers at Derby (WA and Esperance (WA, and confined aquifers at Esperance (WA and Adelaide (SA. The combination of analytic and qualitative approaches offers a more comprehensive and less subjective seawater intrusion characterization than arises from applying the methods in isolation, thereby imparting enhanced confidence in the outcomes. Importantly, active seawater intrusion conditions occur in many of Australia’s confined coastal aquifers, obviating the use of the analytical solution, and suggesting that offshore groundwater resources provide significant contributions to these systems.

  6. Hybrid Optimization of Support Vector Machine for Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    XI Fu-li; YU Song-nian; HAO Wei

    2005-01-01

    Support vector machine (SVM) technique has recently become a research focus in intrusion detection field for its better generalization performance when given less priori knowledge than other soft-computing techniques. But the randomicity of parameter selection in its implement often prevents it achieving expected performance. By utilizing genetic algorithm (GA) to optimize the parameters in data preprocessing and the training model of SVM simultaneously, a hybrid optimization algorithm is proposed in the paper to address this problem. The experimental results demonstrate that it's an effective method and can improve the perfornance of SVM-based intrusion detection system further.

  7. Research and Implementation of Unsupervised Clustering-Based Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    Luo Min; Zhang Huan-guo; Wang Li-na

    2003-01-01

    An unsupervised clustering-based intrusion de tection algorithm is discussed in this paper. The basic idea of the algorithm is to produce the cluster by comparing the distances of unlabeled training data sets. With the classified data instances, anomaly data clusters can be easily identified by normal cluster ratio and the identified cluster can be used in real data detection. The benefit of the algorithm is that it doesnt need labeled training data sets. The experiment concludes that this approach can detect unknown intrusions efficiently in the real network connections via using the data sets of KDD99.

  8. Research and Implementation of Unsupervised Clustering-Based Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    LuoMin; ZhangHuan-guo; WangLi-na

    2003-01-01

    An unsupervised clustering-based intrusion detection algorithm is discussed in this paper. The basic idea of the algorithm is to produce the cluster by comparing the distances of unlabeled training data sets. With the classified data instances, anomaly data clusters can be easily identified by normal duster ratio and the identified cluster can be used in real data detection. The benefit of the algorithm is that it doesn't need labeled training data sets. The experiment coneludes that this approach can detect unknown intrusions efficiently in the real network connections via using the data sets of KDD99.

  9. A Numerical Investigation of Vapor Intrusion — the Dynamic Response of Contaminant Vapors to Rainfall Events

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1 m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in

  10. A numerical investigation of vapor intrusion--the dynamic response of contaminant vapors to rainfall events.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2012-10-15

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in determining

  11. Enhancing collaborative intrusion detection networks against insider attacks using supervised intrusion sensitivity-based trust management model

    DEFF Research Database (Denmark)

    Li, Wenjuan; Meng, Weizhi; Kwok, Lam-For

    2017-01-01

    To defend against complex attacks, collaborative intrusion detection networks (CIDNs) have been developed to enhance the detection accuracy, which enable an IDS to collect information and learn experience from others. However, this kind of networks is vulnerable to malicious nodes which...... of intrusion sensitivity based on expert knowledge. In the evaluation, we compare the performance of three different supervised classifiers in assigning sensitivity values and investigate our trust model under different attack scenarios and in a real wireless sensor network. Experimental results indicate...... are utilized by insider attacks (e.g., betrayal attacks). In our previous research, we developed a notion of intrusion sensitivity and identified that it can help improve the detection of insider attacks, whereas it is still a challenge for these nodes to automatically assign the values. In this article, we...

  12. A note on salt intrusion in funnel-shaped estuaries: Application to the Incomati estuary, Mozambique

    Science.gov (United States)

    Brockway, Rachel; Bowers, David; Hoguane, Antonio; Dove, Veronica; Vassele, Valentina

    2006-01-01

    Salt intrusion in estuaries is important for ecological reasons as well as water extraction purposes. The distance salt intrudes upstream depends on a number of factors, including river discharge, tidal and wind mixing and gravitational circulation. In this paper, an analytical solution is presented for the salt intrusion in a well mixed, funnel-shaped estuary whose cross sectional area decreases exponentially (with decay coefficient β) with distance, x, inland, and in which longitudinal mixing is constant along the length of the estuary. The solution predicts that a graph of the logarithm of salinity against exp ( βx) should be a straight line, with slope proportional to the mixing coefficient K x. The solution is tested against observations from 15 surveys over a four-year period in the Incomati estuary. Good straight line fits, as predicted, are observed on all surveys, with a mean R2 = 0.97. The average value of K x for all surveys is 38 m 2 s -1. The solution is used to make predictions about the minimum river flow required to prevent salt intruding to an extent where it causes a detrimental effect on water extraction. The minimum recommended river flow required to prevent this is 35 m 3 s -1. In recent years, flow has fallen below this level for several months each year.

  13. Episodic intrusion, internal differentiation, and hydrothermal alteration of the miocene tatoosh intrusive suite south of Mount Rainier, Washington

    Science.gov (United States)

    du Bray, E.A.; Bacon, C.R.; John, D.A.; Wooden, J.L.; Mazdab, F.K.

    2011-01-01

    The Miocene Tatoosh intrusive suite south of Mount Rainier is composed of three broadly granodioritic plutons that are manifestations of ancestral Cascades arc magmatism. Tatoosh intrusive suite plutons have individually diagnostic characteristics, including texture, mineralogy, and geochemistry, and apparently lack internal contacts. New ion-microprobe U-Pb zircon ages indicate crystallization of the Stevens pluton ca. 19.2 Ma, Reflection-Pyramid pluton ca. 18.5 Ma, and Nisqually pluton ca. 17.5 Ma. The Stevens pluton includes rare, statistically distinct ca. 20.1 Ma zircon antecrysts. Wide-ranging zircon rare earth element (REE), Hf, U, and Th concentrations suggest late crystallization from variably evolved residual liquids. Zircon Eu/Eu*-Hf covariation is distinct for each of the Reflection-Pyramid, Nisqually, and Stevens plutons. Although most Tatoosh intrusive suite rocks have been affected by weak hydrothermal alteration, and sparse mineralized veins cut some of these rocks, significant base or precious metal mineralization is absent. At the time of shallow emplacement, each of these magma bodies was largely homogeneous in bulk composition and petrographic features, but, prior to final solidification, each of the Tatoosh intrusive suite plutons developed internal compositional variation. Geochemical and petrographic trends within each pluton are most consistent with differential loss of residual melt, possibly represented by late aplite dikes or erupted as rhyolite, from crystal-rich magma. Crystal-rich magma that formed each pluton evidently accumulated in reservoirs below the present level of exposure and then intruded to a shallow depth. Assembled by episodic intrusion, the Tatoosh intrusive suite may be representative of midsized composite plutonic complexes beneath arc volcanoes. ?? 2011 Geological Society of America.

  14. Geology and Geochemistry of Reworking Gold Deposits in Intrusive Rocks of China—Ⅰ. Features of the Intrusive Rocks

    Institute of Scientific and Technical Information of China (English)

    王秀璋; 程景平; 等

    1998-01-01

    Most gold deposits in intrusive rocks were formed as a result of reworking processes.the intrusive rocks containing gold deposits and consisting of ultramafic-mafic,intermediateacid and alkaline rocks of the Archean,Proterozoic,Caledonian,Hercynian and Yenshanian periods occur in cratons,activated zones of cratons and fold belts.Among them,ultramaficmafic rocks,diorite,alkaline rocks,and anorthosite are products of remelting in the mantle or mantle-crust or mantle with crustal contamination,However,auriferous intermediate-acid rocks are products of metasomatic-remelting in auriferous volcainc rocks or auriferous volcanosedimentary rocks in the deep crust.

  15. Potential consequences of saltwater intrusion associated with Hurricanes Katrina and Rita: Chapter 6C in Science and the storms-the USGS response to the hurricanes of 2005

    Science.gov (United States)

    Steyer, Gregory D.; Perez, Brian C.; Piazza, Sarai C.; Suir, Glenn

    2007-01-01

    Hurricanes Katrina and Rita pushed salt water from the Gulf of Mexico well inland into freshwater marsh communities in coastal Louisiana. This paper describes the spatial extent of saltwater intrusion and provides an initial assessment of impacts (salt stress) to coastal marsh vegetation communities.

  16. 10 CFR 63.321 - Individual protection standard for human intrusion.

    Science.gov (United States)

    2010-01-01

    ... IN A GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA Postclosure Public Health and Environmental Standards Human Intrusion Standard § 63.321 Individual protection standard for human intrusion. (a) DOE...

  17. Lunar Intrusive Domes on the Floor of Grimaldi and Near Aristillus

    Science.gov (United States)

    Wöhler, C.; Lena, R.; Pau, K. C.

    2010-03-01

    In this contribution we examine two large lunar domes of probably intrusive origin. The morphometric properties of the domes are derived, and geophysical parameters (intrusion depth, magma pressure) are estimated based on modelling.

  18. The effect of intrusive orthodontic force on dental pulp of adults versus adolescents

    Directory of Open Access Journals (Sweden)

    Mostafa Abtahi

    2016-01-01

    Conclusion: Mild intrusive force in closed apex teeth causes no significant histologic changes in adolescents and adults. However, it seems that inflammatory-related histologic pulpal changes are more severe in adults after one month of intrusion.

  19. Enhancing Battlemind: Preventing PTSD by Coping with Intrusive Thoughts

    Science.gov (United States)

    2014-05-01

    normative across varied populations, those experiencing intrusive thoughts often report that the thoughts are disturbing, and they fear Coping With...tests of a cognitive model of generalized anxiety disorder: Metacognitions and worry in GAD, panic disorder, social phobia , depression, and nonpatients

  20. Revisiting anomaly-based network intrusion detection systems

    NARCIS (Netherlands)

    Bolzoni, Damiano

    2009-01-01

    Intrusion detection systems (IDSs) are well-known and widely-deployed security tools to detect cyber-attacks and malicious activities in computer systems and networks. A signature-based IDS works similar to anti-virus software. It employs a signature database of known attacks, and a successful match

  1. MULTI SCALE TIME SERIES PREDICTION FOR INTRUSION DETECTION

    Directory of Open Access Journals (Sweden)

    G. Palanivel

    2014-01-01

    Full Text Available We propose an anomaly-based network intrusion detection system, which analyzes traffic features to detect anomalies. The proposed system can be used both in online as well as off-line mode for detecting deviations from the expected behavior. Although our approach uses network packet or flow data, it is general enough to be adaptable for use with any other network variable, which may be used as a signal for anomaly detection. It differs from most existing approaches in its use of wavelet transform for generating different time scales for a signal and using these scales as an input to a two-stage neural network predictor. The predictor predicts the expected signal value and labels considerable deviations from this value as anomalies. The primary contribution of our work would be to empirically evaluate the effectiveness of multi resolution analysis as an input to neural network prediction engine specifically for the purpose of intrusion detection. The role of Intrusion Detection Systems (IDSs, as special-purpose devices to detect anomalies and attacks in a network, is becoming more important. First, anomaly-based methods cannot achieve an outstanding performance without a comprehensive labeled and up-to-date training set with all different attack types, which is very costly and time-consuming to create if not impossible. Second, efficient and effective fusion of several detection technologies becomes a big challenge for building an operational hybrid intrusion detection system.

  2. An Overview of IP Flow-Based Intrusion Detection

    NARCIS (Netherlands)

    Sperotto, Anna; Schaffrath, Gregor; Sadre, Ramin; Morariu, Cristian; Pras, Aiko; Stiller, Burkhard

    2010-01-01

    Intrusion detection is an important area of research. Traditionally, the approach taken to find attacks is to inspect the contents of every packet. However, packet inspection cannot easily be performed at high-speeds. Therefore, researchers and operators started investigating alternative approaches,

  3. SSHCure: SSH Intrusion Detection using NetFlow and IPFIX

    NARCIS (Netherlands)

    Hendriks, Luuk; Hofstede, Rick; Sperotto, Anna; Pras, Aiko

    2014-01-01

    With this poster, we present our SSH Intrusion Detection System named SSHCure: it is the first IDS capable of distinguishing successful attacks from unsuccessful attacks, thus detecting actual compromises. As powerful as SSH is to administrators, as attractive it is to anyone with malicious intents.

  4. Neural Network Based Intrusion Detection System for Critical Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Ondrej Linda; Milos Manic

    2009-07-01

    Resiliency and security in control systems such as SCADA and Nuclear plant’s in today’s world of hackers and malware are a relevant concern. Computer systems used within critical infrastructures to control physical functions are not immune to the threat of cyber attacks and may be potentially vulnerable. Tailoring an intrusion detection system to the specifics of critical infrastructures can significantly improve the security of such systems. The IDS-NNM – Intrusion Detection System using Neural Network based Modeling, is presented in this paper. The main contributions of this work are: 1) the use and analyses of real network data (data recorded from an existing critical infrastructure); 2) the development of a specific window based feature extraction technique; 3) the construction of training dataset using randomly generated intrusion vectors; 4) the use of a combination of two neural network learning algorithms – the Error-Back Propagation and Levenberg-Marquardt, for normal behavior modeling. The presented algorithm was evaluated on previously unseen network data. The IDS-NNM algorithm proved to be capable of capturing all intrusion attempts presented in the network communication while not generating any false alerts.

  5. Extension by faulting, stretching and magma intrusion in Ethiopia

    Science.gov (United States)

    Bastow, I. D.; Keir, D.

    2012-12-01

    The 2001-2004 Ethiopia Afar Geoscientific Lithospheric Experiment showed that high seismic wavespeed, dense, mafic crustal intrusions exist beneath many zones of Quaternary magmatism in the Main Ethiopian rift, and that crustal thinning is minimal. From these observations, a consensus quickly emerged that extension presently occurs not by ductile stretching and brittle faulting but by magma intrusion. Striking InSAR images and accompanying seismic data from the 2005 Afar diking episode provided further compelling evidence in support of the magma assisted rifting hypothesis. Patterns of mantle seismic anisotropy, constrained by a combination of body and surface-wave analysis showed that melt intrusion likely also plays an important role in accommodating extension at greater depths in the extending plate. Evidence from further north in Afar, however, where crustal thickness decreases abruptly into the Danakil Depression, is not so easily explained by the magma assisted rifting hypothesis. Subsidence of the newly forming margin towards and below sea level, and eruption of voluminous basalt flows, is likely the result of late-stage thinning of the heavily intruded, weakened plate just before the onset of seafloor spreading. Faulting, stretching and magma intrusion are thus each important, but at different times during breakup. Combining, not isolating, these mechanisms of strain in new rifting models and appreciating how plate strength varies during rifting is essential in developing a clearer understanding of the incomplete geological record that documents continental breakup over time.

  6. A novel feature selection approach for intrusion detection data classification

    NARCIS (Netherlands)

    Ambusaidi, Mohammed A.; He, Xiangjian; Tan, Zhiyuan; Nanda, Priyadarsi; Lu, Liang Fu; Nagar, Upasana T.

    2014-01-01

    Intrusion Detection Systems (IDSs) play a significant role in monitoring and analyzing daily activities occurring in computer systems to detect occurrences of security threats. However, the routinely produced analytical data from computer networks are usually of very huge in size. This creates a

  7. Sensitivity analysis on parameters and processes affecting vapor intrusion risk

    NARCIS (Netherlands)

    Picone, S.; Valstar, J.R.; Gaans, van P.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2012-01-01

    A one-dimensional numerical model was developed and used to identify the key processes controlling vapor intrusion risks by means of a sensitivity analysis. The model simulates the fate of a dissolved volatile organic compound present below the ventilated crawl space of a house. In contrast to the v

  8. Boosting Web Intrusion Detection Systems by Inferring Positive Signatures

    NARCIS (Netherlands)

    Bolzoni, D.; Etalle, Sandro

    2008-01-01

    We present a new approach to anomaly-based network intrusion detection for web applications. This approach is based on dividing the input parameters of the monitored web application in two groups: the "regular" and the "irregular" ones, and applying a new method for anomaly detection on the

  9. SSHCure: a flow-based SSH intrusion detection system

    NARCIS (Netherlands)

    Hellemons, Laurens; Hendriks, Luuk; Hofstede, Rick; Sperotto, Anna; Sadre, Ramin; Pras, Aiko

    2012-01-01

    SSH attacks are a main area of concern for network managers, due to the danger associated with a successful compromise. Detecting these attacks, and possibly compromised victims, is therefore a crucial activity. Most existing network intrusion detection systems designed for this purpose rely on the

  10. Poseidon: a 2-tier anomaly-based intrusion detection system

    NARCIS (Netherlands)

    Bolzoni, Damiano; Zambon, Emmanuele; Etalle, Sandro; Hartel, Pieter

    2005-01-01

    We present Poseidon, a new anomaly based intrusion detection system. Poseidon is payload-based, and presents a two-tier architecture: the first stage consists of a Self-Organizing Map, while the second one is a modified PAYL system. Our benchmarks on the 1999 DARPA data set show a higher detection r

  11. Evaluation of of μ-controller PIR Intrusion Detector

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    West African Journal of Industrial & Academic Research Vol.15 No.1 December 2015. 3 ... Intrusion detection is simply the process of recognizing that an object is located in a place ... the specific application and operational ... Figure 1: Block Diagram Showing Design Modules and the ..... Engineering Science Invention, Vol.

  12. Network Intrusion Detection System Based On Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Vipin Das

    2010-12-01

    Full Text Available Network and system security is of paramount importance in the present data communication environment. Hackers and intruders can create many successful attempts to cause the crash of the networks and web services by unauthorized intrusion. New threats and associated solutions to prevent these threats are emerging together with the secured system evolution. Intrusion Detection Systems (IDS are one of these solutions. The main function of Intrusion Detection System is to protect the resources from threats. It analyzes and predicts the behaviours of users, and then these behaviours will be considered an attack or a normal behaviour. We use Rough Set Theory (RST and Support Vector Machine (SVM to detect network intrusions. First, packets are captured from the network, RST is used to pre-process the data and reduce the dimensions. The features selected by RST will be sent to SVM model to learn and test respectively. The method is effective to decrease the space density of data. The experiments compare the results with Principal Component Analysis (PCA and show RST and SVM schema could reduce the false positive rate and increase the accuracy.

  13. Neural Network Based Intrusion Detection System for Critical Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Todd Vollmer; Ondrej Linda; Milos Manic

    2009-07-01

    Resiliency and security in control systems such as SCADA and Nuclear plant’s in today’s world of hackers and malware are a relevant concern. Computer systems used within critical infrastructures to control physical functions are not immune to the threat of cyber attacks and may be potentially vulnerable. Tailoring an intrusion detection system to the specifics of critical infrastructures can significantly improve the security of such systems. The IDS-NNM – Intrusion Detection System using Neural Network based Modeling, is presented in this paper. The main contributions of this work are: 1) the use and analyses of real network data (data recorded from an existing critical infrastructure); 2) the development of a specific window based feature extraction technique; 3) the construction of training dataset using randomly generated intrusion vectors; 4) the use of a combination of two neural network learning algorithms – the Error-Back Propagation and Levenberg-Marquardt, for normal behavior modeling. The presented algorithm was evaluated on previously unseen network data. The IDS-NNM algorithm proved to be capable of capturing all intrusion attempts presented in the network communication while not generating any false alerts.

  14. Corporate Mergers in the Publishing Industry: Helpful or Intrusive?

    Science.gov (United States)

    Rudman, Herbert C.

    1990-01-01

    Examines the effects of corporate mergers in the publishing industry on the publishing of textbooks and standardized tests. Concludes that restructuring, acquisitions, and mergers have an intrusive effect on established practices of academic publishing and may severely limit the access of scholars to the academic marketplace. (FMW)

  15. Mitigating Intrusion and Vulnerabilities in Cognitive Radio Networks

    Directory of Open Access Journals (Sweden)

    I. Ohaeri

    Full Text Available The deployment of Cognitive Radio Networks has been greatly hindered in spite of its potentials by the rate at which intrusions and vulnerabilities replicate within every domain of the network. Cognitive Radio Network is expected to drive the next generat ...

  16. Estimating salinity intrusion effects due to climate change along the Grand Strand of the South Carolina coast

    Science.gov (United States)

    Conrads, Paul A.; Roehl, Edwin A.; Sexton, Charles T.; Tufford, Daniel L.; Carbone, Gregory J.; Dow, Kristin; Cook, John B.

    2010-01-01

    The ability of water-resource managers to adapt to future climatic change is especially challenging in coastal regions of the world. The East Coast of the United States falls into this category given the high number of people living along the Atlantic seaboard and the added strain on resources as populations continue to increase, particularly in the Southeast. Increased temperatures, changes in regional precipitation regimes, and potential increased sea level would have a great impact on existing hydrological systems in the region. Six reservoirs in North Carolina discharge into the Pee Dee River, which flows 160 miles through South Carolina to the coastal communities near Myrtle Beach, SC. During the Southeast’s record-breaking drought from 1998 to 2002, salinity intrusions inundated a coastal municipal freshwater intake, limiting water supplies. Salinity intrusion results from the interaction of three principal forces - streamflow, mean tidal water levels, and tidal range. To analyze, model, and simulate hydrodynamic behaviors at critical coastal streamgages along the Atlantic Intracoastal Waterway (AIW) near Myrtle Beach, SC, data-mining techniques were applied to over 20 years of hourly streamflow, coastal water-quality, and water-level data. Artificial neural network (ANN) models were trained to learn the variable interactions that cause salinity intrusions. Streamflow from the 12,700 square-mile Pee Dee River Basin that flows into the AIW are input to the model as time-delayed variables and accumulated tributary inflows. Tidal inputs to the models were obtained by decomposing tidal water-level data into a “periodic” signal of tidal range and a “chaotic” signal of mean water levels. The ANN models were able to convincingly reproduce historical behaviors and generate alternative scenarios of interest. To evaluate the impact of climate change on salinity intrusion, inputs of streamflows and mean tidal water levels were modified to incorporate estimated

  17. Effects of climate variability on saltwater intrusions in coastal aquifers in Southern Denmark

    Science.gov (United States)

    Meyer, Rena; Sonnenborg, Torben; Engesgaard, Peter; Høyer, Anne-Sophie; Jørgensen, Flemming; Hisnby, Klaus; Hansen, Birgitte; Jensen, Jørn Bo; Piotrowski, Jan A.

    2016-04-01

    As in many other regions of the world fresh water supply in Denmark is based on groundwater resources. Aquifers in the low-lying areas in the south-west of Jutland are particularly vulnerable to saltwater intrusions which are likely to intensify due to relative sea level rise. To understand the dynamics and development of this complex flow system, the initial hydrodynamic conditions imposed by the last Scandinavian Ice Sheet (SIS) must be taken into account. The whole region has undergone changes in climatic and hydraulic conditions within the last 15000 years that may show influence on the present flow conditions. It is likely that the groundwater-flow dynamics, driven by the postglacial hydraulic head drop and the relative sea level rise are not yet equilibrated. Enhanced by the potential future sea level rise due to climate change, contamination of fresh-water aquifers will continue. The 2800-km2 - large coast-to-coast study area located in the southern part of Jutland was partly overridden by the Weichselian ice sheet. Geophysical and geological mapping shows salt water intrusions up to 20 km inland from the present coast. Based on a geological voxel model spanning Miocene through Quaternary deposits a large-scale 3D numerical groundwater flow and salt water transport model has been developed. It includes density-driven flow and simulates the distribution of the current saltwater intrusions and their evolution during the last 15000 years. Particle tracking and direct age simulations are performed to identify recharge areas and constrain groundwater ages. The simulated ages are compared to ages derived from isotope analysis of groundwater samples both from Miocene and Quaternary aquifers. The origin of the groundwater is determined based on isotopic and chemical composition. Additionally, heavy noble gas analysis is carried out to estimate recharge temperatures and mechanisms at locations where groundwater recharge during the last glaciation is indicated. This

  18. Implementation of Network Intrusion Detection System Based on Density-based Outliers Mining

    Institute of Scientific and Technical Information of China (English)

    Huang,Guangqiu; Peng,Xuyou; LV,Dingquan

    2005-01-01

    The paper puts forward a new method of densitybased anomaly data mining, the method is used to design the engine of network intrusion detection system (NIDS), thus a new NIDS is constructed based on the engine. The NIDS can find new unknown intrusion behaviors, which are used to updated the intrusion rule-base, based on which intrusion detections can be carried out online by the BM pattern match algorithm. Finally all modules of the NIDS are described by formalized language.

  19. Intrusions of a drowsy mind: Neural markers of phenomenological unpredictability

    Directory of Open Access Journals (Sweden)

    Valdas eNoreika

    2015-03-01

    Full Text Available The transition from a relaxed to a drowsy state of mind is often accompanied by hypnagogic experiences: most commonly, perceptual imagery, but also linguistic intrusions, i.e. the sudden emergence of unpredictable anomalies in the stream of inner speech. This study has sought to describe the contents of such intrusions, to verify their association with the progression of sleep onset, and to investigate the electroencephalographic processes associated with linguistic intrusions as opposed to more common hypnagogic perceptual imagery. A single participant attended 10 experimental sessions in the EEG laboratory, where he was allowed to drift into a drowsy state of mind, while maintaining metacognition of his own experiences. Once a linguistic intrusion or a noticeable perceptual image occurred, the participant pressed a button and reported it verbally. An increase in the EEG-defined depth of drowsiness as assessed by the Hori system of sleep onset was observed in the last 20 sec before a button press. Likewise, EEG Dimension of Activation values decreased before the button press, indicating that the occurrence of cognitively incongruous experiences coincides with the rapid change of EEG predictability patterns. EEG hemispheric asymmetry analysis showed that linguistic intrusions had a higher alpha and gamma power in the left hemisphere electrodes, whereas perceptual imagery reports were associated with a higher beta power over the right hemisphere. These findings indicate that the modality as well as the incongruence of drowsiness-related hypnagogic experiences is strongly associated with distinct EEG signatures in this participant. Sleep onset may provide a unique possibility to study the neural mechanisms accompanying the fragmentation of the stream of consciousness in healthy individuals.

  20. Intrusions of autobiographical memories in individuals reporting childhood emotional maltreatment

    Directory of Open Access Journals (Sweden)

    Philip Spinhoven

    2011-09-01

    Full Text Available During childhood emotional maltreatment (CEM negative attitudes are provided to the child (e.g., “you are worthless”. These negative attitudes may result in emotion inhibition strategies in order to avoid thinking of memories of CEM, such as thought suppression. However, thought suppression may paradoxically enhance occurrences (i.e., intrusions of these memories, which may occur immediately or sometime after active suppression of these memories.Until now, studies that examined suppressive coping styles in individuals reporting CEM have utilized self-report questionnaires. Therefore, it is unclear what the consequences will be of emotion inhibition styles on the intrusion of autobiographical memories in individuals reporting CEM.Using a thought suppression task, this study aimed to investigate the experience of intrusions during suppression of, and when no longer instructed to actively suppress, positive and negative autobiographical memories in individuals reporting Low, Moderate, and Severe CEM compared to No Abuse (total N = 83.We found no group differences during active suppression of negative and positive autobiographical memories. However, when individuals reporting Severe CEM were no longer instructed to suppress thinking about the memory, individuals reporting No Abuse, Low CEM, or Moderate CEM reported fewer intrusions of both positive and negative autobiographical memories than individuals reporting Severe CEM. Finally, we found that intrusions of negative memories are strongly related with psychiatric distress.The present study results provide initial insights into the cognitive mechanisms that may underlie the consequences of childhood emotional maltreatment and suggests avenues for successful interventions.For the abstract or full text in other languages, please see Supplementary files under Reading Tools online

  1. Application of a Hidden Bayes Naive Multiclass Classifier in Network Intrusion Detection

    Science.gov (United States)

    Koc, Levent

    2013-01-01

    With increasing Internet connectivity and traffic volume, recent intrusion incidents have reemphasized the importance of network intrusion detection systems for combating increasingly sophisticated network attacks. Techniques such as pattern recognition and the data mining of network events are often used by intrusion detection systems to classify…

  2. A reactive transport investigation of a seawater intrusion experiment in a shallow aquifer, Skansehage Denmark

    DEFF Research Database (Denmark)

    Christensen, Flemming Damgaard; Engesgaard, Peter Knudegaard; Kipp, K.L.

    2001-01-01

    Previous investigations on seawater intrusion have mainly focused on either the physical density flow system with transport of a single non-reactive species or focused on the geochemical aspects neglecting density effects. This study focuses on both the geochemical and physical aspects of seawater...... intrusion and their interaction during an intrusion experiment in a shallow, small-scale coastal aquifer in Denmark....

  3. THE ELEVATION NET FOR THE SALTWATER INTRUSION PHENOMENON ANALYSIS IN THE COASTAL PLAIN OF PISA

    Directory of Open Access Journals (Sweden)

    G. Caroti

    2014-01-01

    The essential foundation to reconstruct the freshwater/saltwater interface, and therefore also for the recognition of the phenomenon of seawater intrusion, is represented by piezometric reconstructions integrated with hydrogeochemical information that can be obtained directly from in-well measurements and indirectly through laboratory tests carried out on samples of water. A serious limitation of the piezometric reconstructions is mostly represented by the margin of approximation with which the elevation of water points has been established, which in turn result in uncertainty in the relationship between piezometric and hydrometric elevation. This paper presents various methodologies, GNSS and conventional, to determine the elevation of piezometers, also evaluating the accuracy obtainable and the requirements in terms of time, personnel and equipment.

  4. The first field-based descriptions of pumping-induced saltwater intrusion and upconing

    Science.gov (United States)

    Houben, Georg; Post, Vincent E. A.

    2016-09-01

    Development of the ideas about the equilibrium between freshwater and saline water has received considerable attention in the literature, but little has been written so far about the earliest scientific works about well salinization. Based on a review of the literature from the second half of the 19th century and the early 20th century, this historical note explores how insights into groundwater abstraction and saltwater intrusion developed, and examples of the earliest field studies are provided. Fundamental research was driven by the need for increasing water supply, but the progress of science did not lead to sustainable management practices everywhere. Research outcomes were shared between scientists of different countries, marking the beginning of coastal hydrogeology as a scientific specialization in the first decade of the 20th century.

  5. 1420 Ma diabasic intrusives from the Mesoproterozoic Singhora Group, Chhattisgarh Supergroup, India: Implications towards non-plume intrusive activity

    Indian Academy of Sciences (India)

    Priyabrata Das; Kaushik Das; Partha Pratim Chakraborty; S Balakrishnan

    2011-04-01

    Besides offering significant clues towards tracking the geochemical evolution of the mantle and architectural reconstruction of different ‘supercontinent’, geochronological and geochemical appraisal of igneous inputs are also important to bracket the depositional time frame of any lithopackage, particularly, the unfossiliferous sedimentary successions. The present study deals with diabasic intrusive within Mesoproterozoic Saraipalli Formation, which is an argillaceous constituent present at the basal part of nearly 400 m thick four-tiered unmetamorphosed but deformed sedimentary succession of Singhora Group, Chhattisgarh Supergroup, central India. The SE–NW trending intrusive comprises mainly of plagioclase and augite together with minor orthopyroxene, biotite and opaque minerals. Though some plagioclase laths are partially sericitized, the ophitic-to-subophitic texture of the rock is well preserved. Major and trace element geochemical data indicate that this intrusive is basalt-to-basaltic andesite in character and of subalkaline basalt affinity. Multi-element plot shows overall LILE-enrichment and enrichment of Pb and slight depletion of Nb and P, coupled with moderate La/Nb and Th/Nb ratios. Zr, Y and Nb ternary diagrams plot in the fields of within plate basalt. Selected HFSE ratios indicate a non-plume source with crustal assimilation/sediment mixing. Sm–Nd and Rb–Sr isotope data show that the intrusive has Srinitial and Ndinitial of 0.709377–0.706672 and 0.510919–0.510815, respectively. Positive tNd [t = 1420 Ma] values (+0.3 to + 2.3) indicate depleted isotopic nature of their protolith. The calculated DM age is 1.7–1.9 Ga. The mineral-whole rock isochron data (Sm–Nd systematics) of the intrusive implies an emplacement age of ca. 1420 Ma. Considering synchronous terrain boundary shear zone development in Bastar craton on the southeastern part of the Singhora basin, mafic magmatism in Eastern Ghats and large-scale basic intrusion in Sausar

  6. Imaging Saltwater Intrusion Along the Coast of Monterey Bay Using Long-Offset Electrical Resistivity Tomography

    Science.gov (United States)

    Goebel, M.; Knight, R. J.; Pidlisecky, A.

    2016-12-01

    Coastal regions represent a complex dynamic interface where saltwater intrusion moves seawater landward and groundwater discharge moves freshwater seaward. These processes can have a dramatic impact on water quality, affecting both humans and coastal ecosystems. The ability to map the subsurface distribution of fresh and salt water is a critical step in predicting and managing water quality in coastal regions. This is commonly accomplished using wells, which are expensive and provide point information, which may fail to capture the spatial complexity in subsurface conditions. We present an alternate method for acquiring data, long-offset Electrical Resistivity Tomography (ERT), which is non-invasive, cost effective, and can address the problem of poor spatial sampling. This geophysical method can produce continuous profiles of subsurface electrical resistivity to a depth of 300 m, with spatial resolution on the order of tens of meters. Our research focuses on the Monterey Bay region, where sustained groundwater extraction over the past century has led to significant saltwater intrusion. ERT was acquired along 40 kilometers of the coast using the roll along method, allowing for continuous overlap in data acquisition. Electrodes were spaced every 22.2 m, with a total of 81 electrodes along the 1.8 km active cable length. The data show a complex distribution of fresh and salt water, influenced by geology, groundwater pumping, recharge, and land-use. While the inverted ERT resistivity profiles correspond well with existing data sets and geologic interpretations in the region, the spatial complexity revealed through the ERT data goes beyond what is known from traditional data sources alone. This leads us to conclude that this form of data can be extremely useful in informing and calibrating groundwater flow models, making targeted management decisions, and monitoring changes in subsurface salinities over time.

  7. Groundwater Modeling in Coastal Arid Regions Under the Influence of Marine Saltwater Intrusion

    Science.gov (United States)

    Walther, Marc; Kolditz, Olaf; Grundmann, Jens; Liedl, Rudolf

    2010-05-01

    The optimization of an aquifer's "safe yield", especially within agriculturally used regions, is one of the fundamental tasks for nowaday's groundwater management. Due to the limited water ressources in arid regions, conflict of interests arise that need to be evaluated using scenario analysis and multicriterial optimization approaches. In the context of the government-financed research project "International Water Research Alliance Saxony" (IWAS), the groundwater quality for near-coastal, agriculturally used areas is investigated under the influence of marine saltwater intrusion. Within the near-coastal areas of the study region, i.e. the Batinah plains of Northern Oman, an increasing agricultural development could be observed during the recent decades. Simultaneously, a constant lowering of the groundwater table was registered, which is primarily due to the uncontrolled and unsupervised mining of the aquifers for the local agricultural irrigation. Intensively decreased groundwater levels, however, cause an inversion of the hydraulic gradient which is naturally aligned towards the coast. This, in turn,leads to an intrusion of marine saltwater flowing inland, endangering the productivity of farms near the coast. Utilizing the modeling software package OpenGeoSys, which has been developed and constantly enhanced by the Department of Environmental Informatics at the Helmholtz Centre for Environmental Research Leipzig (UFZ; Kolditz et al., 2008), a three-dimensional, density-dependent model including groundwater flow and mass transport is currently being built up. The model, comprehending three selected coastal wadis of interest, shall be used to investigate different management scenarios. The main focus of the groundwater modelling are the optimization of well positions and pumping schemes as well as the coupling with a surface runoff model, which is also used for the determination of the groundwater recharge due to wadi runoff downstream of retention dams. Based on

  8. Immiscibility of Fluid Phases at Magmatic-hydrothermal Transition: Formation of Various PGE-sulfide Mineralization for Layered Basic Intrusions

    Science.gov (United States)

    Zhitova, L.; Borisenko, A.; Morgunov, K.; Zhukova, I.

    2007-12-01

    Fluid inclusions in quartz of the Merensky Reef (Bushveld Complex, South Africa) and the Chineisky Pluton (Transbaikal Region, Russia) were studied using cryometry, microthermometry, Raman-spectroscopy, LA ICP- MS, scanning electronic microscopy, gas-chromatography and isotopic methods. This allowed us to document some examples of fluid phase separation resulting in formation of different types of PGE-sulfide mineralization for layered basic intrusions. The results obtained show at least three generations of fluid separated from boiling residual alumosilicate intercumulus liquid of the Merensky Reef. The earliest fluid phase composed of homogenous high-dense methane and nitrogen gas mixture was identified in primary gas and co-existing anomalous fluid inclusions from symplectitic quartz. The next generation, heterophase fluid, composed of brines containing a free low-dense (mostly of carbon dioxide) gas phase, was observed in primary multiphase and coexisting gas-rich inclusions of miarolitic quartz crystals. The latest generation was also a heterophase fluid (low salinity water-salt solution and free low-dense methane gas phase) found in primary water-salt and syngenetic gas inclusions from peripheral zones of miarolitic quartz crystals. For the Chineisky Pluton reduced endocontact magmatogene fluids changed to oxidized low salinity hydrothermal fluids in exocontact zone. This resulted in formation of sulfide-PGE enrichment marginal zones of intrusion. The results obtained give us a possibility to suggest that: 1) Fluid phase separation is a typical feature of magmatogene fluids for layered basic intrusions. 2) Reduced fluids can extract and transport substantial PGE and sulfide concentrations. 3) Oxidation of reduced fluids is one of the most important geochemical barriers causing abundant PGE minerals and sulfides precipitation. This in turn results in both formation of PGE reefs or enriched contact zones of layered basic intrusions. This work was supported by

  9. Syn-collision Hairhan layered intrusion, Lakes Zone, Western Mongolia

    Science.gov (United States)

    Vishnevskiy, A. V.; Izokh, A. E.; Kalugin, V. M.; Gertner, I. F.

    2012-04-01

    In the structure of the Lakes Zone of Western Mongolia, which is reconstructed as the Early Cambrian island arc (Lakes island arc terrane), there are several groups of contiguous space gabbroic intrusions, merged in Hirgisnuur complex. The largest (70 km2) is Hairhan intrusion, located in the central part of the Lake Zone in the Bumbat-Hairhan ridge. The structure of the intrusion disturbed by later tectonic movements and the subsequent formation of Cambrian granitoids Tohtoginshil complex. The structures of the body are two groups of rocks: layered series and marginal facies, fragmentary spread to the periphery of intrusion. Gabbronorites of marginal facies have intrusive contacts with the sedimentary rocks of Early Cambrian age Burgastay formation. The marginal facies, apparent thickness which is 1.5 km, is composed primarily of non-olivine gabbronorites in which there is trachytoid and sometimes bedding. Layered series composes the central part of the Hairhan intrusion, the direction of layering has a northwest strike, coaxial with the long axis of the intrusion. The lower part of the layered series consists mainly troctolites with minor olivine gabbroids. The upper part of the layered series consists mainly of olivine gabbro, troctolite occur here less frequently also observed small schlieren anorthosites. Of particular interest is the horizon taxitic gabbro and being above it - the horizon orbicular gabbro at the top of the layered series. The rocks are widely manifested magmatic disruptive and plastic deformation - both macro and micro levels. They are expressed in the collapse of layering of elements in small folds of varying amplitude (typically to a few tens centimeters), often passing into areas and zones taxitic disruption. The greatest number of these structural elements characteristic of the upper part of the layered series, including the orbicular gabbro and troctolites taxitic horizons. These features indicate intensive tectonic processes that

  10. Current challenges using models to forecast seawater intrusion: lessons from the Eastern Shore of Virginia, USA

    Science.gov (United States)

    Sanford, Ward E.; Pope, Jason P.

    2010-01-01

    A three-dimensional model of the aquifer system of the Eastern Shore of Virginia, USA was calibrated to reproduce historical water levels and forecast the potential for saltwater intrusion. Future scenarios were simulated with two pumping schemes to predict potential areas of saltwater intrusion. Simulations suggest that only a few wells would be threatened with detectable salinity increases before 2050. The objective was to examine whether salinity increases can be accurately forecast for individual wells with such a model, and to address what the challenges are in making such model forecasts given current (2009) simulation capabilities. The analysis suggests that even with current computer capabilities, accurate simulations of concentrations within a regional-scale (many km) transition zone are computationally prohibitive. The relative paucity of data that is typical for such regions relative to what is needed for accurate transport simulations suggests that even with an infinitely powerful computer, accurate forecasting for a single well would still be elusive. Useful approaches may include local-grid refinement near wells and geophysical surveys, but it is important to keep expectations for simulated forecasts at wells in line with chloride concentration and other data that can be obtained at that local scale.

  11. A Real Time Intrusion Aggregation And Prevention Technique

    Directory of Open Access Journals (Sweden)

    Fouzia Sultana

    2013-03-01

    Full Text Available Alert aggregation is an important subtask of intrusion detection. The goal is to identify and to cluster different alerts produced by low-level intrusion detection systems, firewalls, etc. belonging to a specific attack instance which has been initiated by an attacker at a certain point in time. Thus, meta-alerts can be generated for the clusters that contain all the relevant information whereas the amount of data (i.e., alerts can be reduced substantially. Meta-alerts may then be the basis for reporting to security experts or for communication within a distributed intrusion detection system. We propose a novel technique for online alert aggregation which is based on a dynamic, probabilistic model of the current attack situation. Basically, it can be regarded as a data stream version of a maximum likelihood approach for the estimation of the model parameters. With three benchmark data sets, we demonstrate that it is possible to achieve reduction rates of up to 99.96 percent while the number of missing meta-alerts is extremely low. In addition, meta-alerts are generated with a delay of typically only a few seconds after observing the first alert belonging to a new attack instance. Two types of intrusions are detected in this work: Firstly a spam attack is detected based on the blacklisted IP addresses from Stop Forum Spam and secondly packet level intrusion is detected based on KDDcup data. A packet sniffer is designed which keeps sniffing and extracting all the packets that are exchanged over internet interface. The packets are filtered and the headers are extracted. The headers are further subdivided into TCP, IP and UDP headers. ICMP packets are then separated. The data is matched with the database intrusion entries using fast string matching techniques and possible attack entries are marked with different color codes. An attack signature may be visible in any header of the same packet. In such cases, the alerts are aggregated and a single

  12. Semi-non-intrusive objective intelligibility measure using spatial filtering in hearing aids

    DEFF Research Database (Denmark)

    Sørensen, Charlotte; Boldt, Jesper Bünsow; Gran, Frederik;

    2016-01-01

    Reliable non-intrusive online assessment of speech intelligibility can play a key role for the functioning of hearing aids, e.g. as guidance for adjusting the hearing aid settings to the environment. While existing intrusive metrics can provide a precise and reliable measure, the current non......-intrusive metrics have not been able to achieve acceptable intelligibility predictions. This paper presents a new semi-non-intrusive intelligibility measure based on an existing intrusive measure, STOI, where an estimate of the clean speech is extracted using spatial filtering in the hearing aid. The results...

  13. EARLY WARNING MODEL OF NETWORK INTRUSION BASED ON D-S EVIDENCE THEORY

    Institute of Scientific and Technical Information of China (English)

    Tian Junfeng; Zhai Jianqiang; Du Ruizhong; Huang Jiancai

    2005-01-01

    Application of data fusion technique in intrusion detection is the trend of nextgeneration Intrusion Detection System (IDS). In network security, adopting security early warning technique is feasible to effectively defend against attacks and attackers. To do this, correlative information provided by IDS must be gathered and the current intrusion characteristics and situation must be analyzed and estimated. This paper applies D-S evidence theory to distributed intrusion detection system for fusing information from detection centers, making clear intrusion situation, and improving the early warning capability and detection efficiency of the IDS accordingly.

  14. A Pattern Matching Algorithm for Reducing False Positive in Signature Based Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    T. Sree Kala,

    2016-04-01

    Full Text Available Nowadays the organizations are facing the number of threats every day in the form of viruses and attack etc. Since many different mechanisms were preferred by organizations in the form of intrusion detection and prevention system to protect its organizations from these kinds of attacks. Intrusion Detection System (IDS is considered as a system integrated with intelligent subsystems. In this paper the signature based intrusion detection system is discussed. There are different pattern matching algorithms available to detect intrusion. Brute force and Knuth-Morris-Pratt are the single keyword pattern matching algorithms. If one or more occurrence of pattern present in the input text, then there is an intrusion and the intrusion alarm will be sent. The occurrence of false alarm will be high in intrusion detection. In this paper the string matching algorithm to reduce the percentage of false alarm will be discussed.

  15. Energy transport processes in a brittle ductile intrusive model of the Taupo Volcanic Zone, New Zealand

    Science.gov (United States)

    Weir, Graham J.

    1998-08-01

    The implications of the findings of recent GPS and micro-seismic studies in the Taupo Volcanic Zone (TVZ), New Zealand, on models of processes transporting mass, heat and chemicals are discussed. It is argued that in addition to the well established process of groundwater convection extracting heat and chemicals by interacting with magmatic intrusives under the TVZ, that two other processes may be important. Firstly, the existence of a ductile layer with very low permeability between about 8 to 15 km depth will produce a region of `enhanced conduction' in which very high conductive fluxes of energy arise from a temperature distribution which varies exponentially with depth. Secondly, water may transport up through the ductile layer, as a result of extensional processes in the ductile region. If extension is occurring at about 8 mm/yr, then geothermal heat transfer in the TVZ of about 4200 MW is made up from about 1200 MW from the cooling of intrusives in the brittle region in the upper 8 km; of about an additional 1900 MW of conducted heat entering the brittle region from the ductile region; and about an additional 1100 MW from water transport through the ductile region. Provided this water flow has a chloride concentration similar to that emitted from nearby volcanoes, then the total chloride transport from the TVZ is about 3.5 kg/s, as suggested by average enthalpy to chloride ratios in the TVZ of about 1.2 MJ/g. The present high heat and mass transport processes in the TVZ are assumed to result from the passive filling of volume created from extensional processes under the TVZ, plus conductive and/or convective heating processes below 15 km depth.

  16. A survey on RBF Neural Network for Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    Henali Sheth

    2014-12-01

    Full Text Available Network security is a hot burning issue nowadays. With the help of technology advancement intruders or hackers are adopting new methods to create different attacks in order to harm network security. Intrusion detection system (IDS is a kind of security software which inspects all incoming and outgoing network traffic and it will generate alerts if any attack or unusual behavior is found in a network. Various approaches are used for IDS such as data mining, neural network, genetic and statistical approach. Among this Neural Network is more suitable approach for IDS. This paper describes RBF neural network approach for Intrusion detection system. RBF is a feed forward and supervise technique of neural network.RBF approach has good classification ability but its performance depends on its parameters. Based on survey we find that RBF approach has some short comings. In order to overcome this we need to do proper optimization of RBF parameters.

  17. Non intrusive check valve diagnostics at Bruce A

    Energy Technology Data Exchange (ETDEWEB)

    Marsch, S.P. [Ontario Hydro, Bruce Nuclear Generating Station A, Tiverton, ON (Canada)

    1997-07-01

    Bruce A purchased non intrusive check valve diagnostic equipment in 1995 to ensure operability and availability of critical check valves in the Station. Diagnostics can be used to locate and monitor check valve degradation modes. Bruce A initiated a pilot program targeting check valves with flow through them and ones that completed open or close cycles. Approaches to determine how to confirm operability of passive check valves using non intrusive techniques were explored. A sample population of seventy-three check valves was selected to run the pilot program on prior to complete implementation. The pilot program produced some significant results and some inconclusive results. The program revealed a major finding that check valve performance modeling is required to ensure continuous operability of check valves. (author)

  18. Analysis of transient saltwater intrusion in costal aquifers

    Science.gov (United States)

    Chang, Y.; Yeh, H.

    2009-12-01

    In a costal aquifer, the seawater intrusion is a classic environmental and economical problem in groundwater hydrology. For modeling this phenomenon, the Henry’s formulation was usually adopted to describe the coupled system of flow and transport equations with variable density. However, it is an arduous task to solve such a problem due to the complexity of the coupled governing equations. For practical applicability, the mixed boundary condition which differs from the Dirichlet boundary condition at the coastal side in Henry’s problem is considered in this study. A depth of interface between freshwater and seawater is specified at the coast boundary and the Neumann and Dirichlet conditions are used, respectively, to describe the costal boundary. The perturbation method with a small parameter is used to decouple the groundwater flow and transport equations and derive the solution for the transient saltwater intrusion model. The model will be compared with some results obtained from finite element simulations.

  19. Vapor intrusion in soils with multimodal pore-size distribution

    Directory of Open Access Journals (Sweden)

    Alfaro Soto Miguel

    2016-01-01

    Full Text Available The Johnson and Ettinger [1] model and its extensions are at this time the most widely used algorithms for estimating subsurface vapor intrusion into buildings (API [2]. The functions which describe capillary pressure curves are utilized in quantitative analyses, although these are applicable for porous media with a unimodal or lognormal pore-size distribution. However, unaltered soils may have a heterogeneous pore distribution and consequently a multimodal pore-size distribution [3], which may be the result of specific granulometry or the formation of secondary porosity related to genetic processes. The present paper was designed to present the application of the Vapor Intrusion Model (SVI_Model to unsaturated soils with multimodal pore-size distribution. Simulations with data from the literature show that the use of a multimodal model in soils with such pore distribution characteristics could provide more reliable results for indoor air concentration, rather than conventional models.

  20. Intrusion Protection against SQL Injection Attacks Using a Reverse Proxy

    Directory of Open Access Journals (Sweden)

    S. Fouzul Hidhaya

    2012-07-01

    Full Text Available In this era where Internet has captured the world, level of security that this Internet provides has not grown as fast as the Internet application. Internet has eased the life of human in numerous ways, but the drawbacks like the intrusions that are attached with the Internet applications sustains the growth of these applications. One such intrusion is the SQL Injection attacks (SQLIA. Since SQLIA contributes 25% of the total Internet attacks, much research is being carried out in this area. In this paper we propose a method to detect the SQL injection. We use a Reverse proxy and MD5 algorithm to check out SQL injection in user input. Using grammar expressions rules we check for SQL injection in URL’s. This system has been tested on standard test bed applications and our work has shown significant improvement detecting and curbing the SQLIA.

  1. Weaknesses, Vulnerabilities And Elusion Strategies Against Intrusion Detection Systems

    Directory of Open Access Journals (Sweden)

    Hossein Jadidoleslamy

    2012-09-01

    Full Text Available One of most important existent issues in information security application domain is Intrusion Detection System (IDS; IDS is a defensive-aggressive system to protect information, verifying and responding tooccurring attacks on computer systems and networks. This paper discusses different topics including presenting some strategies against IDSs to passing from them; this leads to improving detection level and performance of IDS; also, this paper considers some intrusion tools, new attacks patterns and trackingprevention techniques. In addition, it discusses vulnerabilities, security holes and IDSs' structural and systemic problems to eliminating defects, reducing penetrates and correcting their behavior. Finally, it leads to increasing the functionality coefficient of IDSs, promoting the security level of computer systems and networks, increasing the trust of authorized users. So, the proposed methods in this paper can apply to improving the IDSs by using inverse engineering methods.

  2. Waste Management Policy Framework to Mitigate Terrorist Intrusion Activities

    Energy Technology Data Exchange (ETDEWEB)

    Redus, Kenneth, S.

    2003-02-26

    A policy-directed framework is developed to support US Department of Energy (DOE) counterterrorism efforts, specifically terrorist intrusion activities that affect of Environmental Management (EM) programs. The framework is called the Security Effectiveness and Resource Allocation Definition Forecasting and Control System (SERAD-FACS). Use of SERAD-FACS allows trade-offs between resources, technologies, risk, and Research and Development (R&D) efforts to mitigate such intrusion attempts. Core to SERAD-FACS is (1) the understanding the perspectives and time horizons of key decisionmakers and organizations, (2) a determination of site vulnerabilities and accessibilities, and (3) quantifying the measures that describe the risk associated with a compromise of EM assets. The innovative utility of SERAD-FACS is illustrated for three integrated waste management and security strategies. EM program risks, time delays, and security for effectiveness are examined to demonstrate the significant cost and schedule impact terrorist activities can have on cleanup efforts in the DOE complex.

  3. IDPS: An Integrated Intrusion Handling Model for Cloud

    CERN Document Server

    Alsafi, Hassen Mohammed; Pathan, Al-Sakib Khan

    2012-01-01

    Today, many organizations are moving their computing services towards the Cloud. This makes their computer processing available much more conveniently to users. However, it also brings new security threats and challenges about safety and reliability. In fact, Cloud Computing is an attractive and cost-saving service for buyers as it provides accessibility and reliability options for users and scalable sales for providers. In spite of being attractive, Cloud feature poses various new security threats and challenges when it comes to deploying Intrusion Detection System (IDS) in Cloud environments. Most Intrusion Detection Systems (IDSs) are designed to handle specific types of attacks. It is evident that no single technique can guarantee protection against future attacks. Hence, there is a need for an integrated scheme which can provide robust protection against a complete spectrum of threats. On the other hand, there is great need for technology that enables the network and its hosts to defend themselves with s...

  4. Non intrusive check valve diagnostics at Bruce A

    Energy Technology Data Exchange (ETDEWEB)

    Marsch, S.P. [Ontario Hydro, Bruce Nuclear Generating Station A, Tiverton, ON (Canada)

    1997-07-01

    Bruce A purchased non intrusive check valve diagnostic equipment in 1995 to ensure operability and availability of critical check valves in the Station. Diagnostics can be used to locate and monitor check valve degradation modes. Bruce A initiated a pilot program targeting check valves with flow through them and ones that completed open or close cycles. Approaches to determine how to confirm operability of passive check valves using non intrusive techniques were explored. A sample population of seventy-three check valves was selected to run the pilot program on prior to complete implementation. The pilot program produced some significant results and some inconclusive results. The program revealed a major finding that check valve performance modeling is required to ensure continuous operability of check valves. (author)

  5. Misuse and intrusion detection at Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, K.A.; Neuman, M.C.; Simmonds, D.D.; Stallings, C.A.; Thompson, J.L.; Christoph, G.G.

    1995-04-01

    An effective method for detecting computer misuse is the automatic auditing and analysis of on-line user activity. This activity is reflected in system audit records, in system vulnerability postures, and in other evidence found through active system testing. Since 1989 we have implemented a misuse and intrusion detection system at Los Alamos. This is the Network Anomaly Detection and Intrusion Reporter, or NADIR. NADIR currently audits a Kerberos distributed authentication system, file activity on a mass, storage system, and four Cray supercomputers that run the UNICOS operating system. NADIR summarizes user activity and system configuration in statistical profiles. It compares these profiles to expert rules that define security policy and improper or suspicious behavior. It reports suspicious behavior to security auditors and provides tools to aid in follow-up investigations, As NADIR is constantly evolving, this paper reports its development to date.

  6. A Neural Network Approach for Misuse and Anomaly Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    YAO Yu; YU Ge; GAO Fu-xiang

    2005-01-01

    An MLP(Multi-Layer Perceptron)/Elman neural network is proposed in this paper, which realizes classification with memory of past events using the real-time classification of MLP and the memorial functionality of Elman. The system's sensitivity for the memory of past events can be easily reconfigured without retraining the whole network. This approach can be used for both misuse and anomaly detection system. The intrusion detection systems(IDSs) using the hybrid MLP/Elman neural network are evaluated by the intrusion detection evaluation data sponsored by U. S. Defense Advanced Research Projects Agency (DARPA). The results of experiment are presented in Receiver Operating Characteristic (ROC) curves. The capabilites of these IDSs to identify Deny of Service(DOS) and probing attacks are enhanced.

  7. Management of intrusive luxation with immediate surgical repositioning

    Directory of Open Access Journals (Sweden)

    Mazumdar Dibyendu

    2009-01-01

    Full Text Available Intrusive luxation is one of the most severe forms of traumatic injuries in which the affected tooth is forced to displace deeper into the alveolus. As a consequence of this type of injury, maximum damage occurs to the pulp and all the supporting structures. This report presents a case of severe intrusive luxation of mature maxillary central and lateral incisor in a 40-year-old male. The intruded tooth was immediately repositioned (surgical extrusion and splinted within hours following injury. Antibiotic therapy was initiated at the time of repositioning and maintained for 5 days. Pulp removal and calcium hydroxide treatment of the root canal was carried out after repositioning. Splint was removed 2 months later. Definitive root canal treatment with Gutta percha was accomplished at a later appointment. Clinical and radiographic examination 6, 12 and 24 months after the surgical extrusion revealed satisfactory progressive apical and periodontal healing.

  8. Novel Intrusion Detection using Probabilistic Neural Network and Adaptive Boosting

    CERN Document Server

    Tran, Tich Phuoc; Tran, Dat; Nguyen, Cuong Duc

    2009-01-01

    This article applies Machine Learning techniques to solve Intrusion Detection problems within computer networks. Due to complex and dynamic nature of computer networks and hacking techniques, detecting malicious activities remains a challenging task for security experts, that is, currently available defense systems suffer from low detection capability and high number of false alarms. To overcome such performance limitations, we propose a novel Machine Learning algorithm, namely Boosted Subspace Probabilistic Neural Network (BSPNN), which integrates an adaptive boosting technique and a semi parametric neural network to obtain good tradeoff between accuracy and generality. As the result, learning bias and generalization variance can be significantly minimized. Substantial experiments on KDD 99 intrusion benchmark indicate that our model outperforms other state of the art learning algorithms, with significantly improved detection accuracy, minimal false alarms and relatively small computational complexity.

  9. An Efficient Fuzzy Clustering-Based Approach for Intrusion Detection

    CERN Document Server

    Nguyen, Huu Hoa; Darmont, Jérôme

    2011-01-01

    The need to increase accuracy in detecting sophisticated cyber attacks poses a great challenge not only to the research community but also to corporations. So far, many approaches have been proposed to cope with this threat. Among them, data mining has brought on remarkable contributions to the intrusion detection problem. However, the generalization ability of data mining-based methods remains limited, and hence detecting sophisticated attacks remains a tough task. In this thread, we present a novel method based on both clustering and classification for developing an efficient intrusion detection system (IDS). The key idea is to take useful information exploited from fuzzy clustering into account for the process of building an IDS. To this aim, we first present cornerstones to construct additional cluster features for a training set. Then, we come up with an algorithm to generate an IDS based on such cluster features and the original input features. Finally, we experimentally prove that our method outperform...

  10. Integrating Innate and Adaptive Immunity for Intrusion Detection

    CERN Document Server

    Tedesco, Gianni; Aickelin, Uwe

    2010-01-01

    Network Intrusion Detection Systems (NDIS) monitor a network with the aim of discerning malicious from benign activity on that network. While a wide range of approaches have met varying levels of success, most IDS's rely on having access to a database of known attack signatures which are written by security experts. Nowadays, in order to solve problems with false positive alters, correlation algorithms are used to add additional structure to sequences of IDS alerts. However, such techniques are of no help in discovering novel attacks or variations of known attacks, something the human immune system (HIS) is capable of doing in its own specialised domain. This paper presents a novel immune algorithm for application to an intrusion detection problem. The goal is to discover packets containing novel variations of attacks covered by an existing signature base.

  11. NETWORK INTRUSION DETECTION METHOD BASED ON RS-MSVM

    Institute of Scientific and Technical Information of China (English)

    Xiao Yun; Han Chongzhao; Zheng Qinghua; Zhang Junjie

    2006-01-01

    A new method called RS-MSVM (Rough Set and Multi-class Support Vector Machine) is proposed for network intrusion detection. This method is based on rough set followed by MSVM for attribute reduction and classification respectively. The number of attributes of the network data used in this paper is reduced from 41 to 30 using rough set theory. The kernel function of HVDM-RBF (Heterogeneous Value Difference Metric Radial Basis Function), based on the heterogeneous value difference metric of heterogeneous datasets, is constructed for the heterogeneous network data. HVDM-RBF and one-against-one method are applied to build MSVM. DARPA (Defense Advanced Research Projects Agency) intrusion detection evaluating data were used in the experiment. The testing results show that our method outperforms other methods mentioned in this paper on six aspects: detection accuracy, number of support vectors, false positive rate, false negative rate, training time and testing time.

  12. Flexible Training's Intrusion on Work/Life Balance

    OpenAIRE

    Zane BERGE; TAKIYA, Seema

    2005-01-01

    Flexible Training's Intrusion on Work/Life Balance Seema TAKIYAJennifer ARCHBOLDZane BERGEBaltimore, USA Learning interventions should be aligned with the human learning system. To be effective, they have to support human learning, not work against it. Thalheimer, 2004 ABSTRACT With more companies allowing flextime, more access to elearning, and telecomuting, the line between workplace flexibility and work-life balance begins to blur. Companies sell to employees the flexibility of being ab...

  13. Dynamic Probing for Intrusion Detection under Resource Constraints

    Science.gov (United States)

    2013-06-01

    performance measure of regret, defined as the performance loss compared to that of a genie who knows the entire attack processes a priori and probes...performance as that of the omniscient genie . Index Terms—Intrusion detection, dynamic probing, non- stochastic multi-armed bandit, regret. I...dynamic probing strategy under the performance measure of regret, de ned as the performance loss compared to that of a genie who knows the entire attack

  14. An Isolation Intrusion Detection System for Hierarchical Wireless Sensor Networks

    OpenAIRE

    Rung-Ching Chen; Chia-Fen Hsieh; Yung-Fa Huang

    2010-01-01

    A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor environmental conditions, such as battlefield data and personal health information, and some environment limited resources. To avoid malicious damage is important while information is transmitted in wireless network. Thus, Wireless Intrusion Detection Systems are crucial to safe operation in wireless sensor networks. Wireless networks are subject ...

  15. Intrusion Detection Forecasting Using Time Series for Improving Cyber Defence

    OpenAIRE

    Abdullah, Azween Bin; Pillai, Thulasyammal Ramiah; Cai, Long Zheng

    2015-01-01

    The strength of time series modeling is generally not used in almost all current intrusion detection and prevention systems. By having time series models, system administrators will be able to better plan resource allocation and system readiness to defend against malicious activities. In this paper, we address the knowledge gap by investigating the possible inclusion of a statistical based time series modeling that can be seamlessly integrated into existing cyber defense system. Cyber-attack ...

  16. A Simulated Multiagent-Based Architecture for Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    Onashoga S. Adebukola

    2013-04-01

    Full Text Available In this work, a Multiagent-based architecture for Intrusion Detection System (MIDS is proposed to overcome the shortcoming of current Mobile Agent-based Intrusion Detection System. MIDS is divided into three major phases namely: Data gathering, Detection and the Response phases. The data gathering stage involves data collection based on the features in the distributed system and profiling. The data collection components are distributed on both host and network. Closed Pattern Mining (CPM algorithm is introduced for profiling users’ activities in network database. The CPM algorithm is built on the concept of Frequent Pattern-growth algorithm by mining a prefix-tree called CPM-tree, which contains only the closed itemsets and its associated support count. According to the administrator’s specified thresholds, CPM-tree maintains only closed patterns online and incrementally outputs the current closed frequent pattern of users’ activities in real time. MIDS makes use of mobile and static agents to carry out the functions of intrusion detection. Each of these agents is built with rule-based reasoning to autonomously detect intrusions. Java 1.1.8 is chosen as the implementation language and IBM’s Java based mobile agent framework, Aglet 1.0.3 as the platform for running the mobile and static agents. In order to test the robustness of the system, a real-time simulation is carried out on University of Agriculture, Abeokuta (UNAAB network dataset and the results showed an accuracy of 99.94%, False Positive Rate (FPR of 0.13% and False Negative Rate (FNR of 0.04%. This shows an improved performance of MIDS when compared with other known MA-IDSs.

  17. Intrusion Detection System Using Hierarchical GMM and Dimensionality Reduction

    Directory of Open Access Journals (Sweden)

    L. Maria Michael

    2012-07-01

    Full Text Available The focus of this chapter is to provide the effective intrusion detection technique to protect Web server. The IDS protects an server from malicious attacks from the Internet if someone tries to break in through the firewall and tries to have access on any system in the trusted side and alerts the system administrator in case there is a breach in security. Gaussian Mixture Models (GMMs are among the most statistically mature methods for clustering the data. Intrusion detection can be divided into anomaly detection and misuse detection. Misuse detection model is to collect behavioral features of non-normal operation and establish related feature library. In the existing system of anomaly based Intrusion Detection System, the work is based on the number of attacks on the network and using decision tree analysis for rule matching and grading. We are proposing an IDS approach that will use signature based and anomaly based identification scheme. And we are also proposing the rule pruning scheme with GMM(Gaussian Mixture Model. It does facilitate efficient way of handling large amount of rules. And we are planned to compare the performance of the IDS on different models. The Dimension Reduction focuses on using information obtained KDD Cup 99 data set for the selection of attributes to identify the type of attacks. The dimensionality reduction is performed on 41 attributes to 14 and 7 attributes based on Best First Search method and then apply the two classifying Algorithms ID3 and J48 Keywords-Intrusion detection, reliable networks, malicious routers, internet dependability, tolerance.

  18. A Subset Feature Elimination Mechanism for Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    Herve Nkiama

    2016-04-01

    Full Text Available several studies have suggested that by selecting relevant features for intrusion detection system, it is possible to considerably improve the detection accuracy and performance of the detection engine. Nowadays with the emergence of new technologies such as Cloud Computing or Big Data, large amount of network traffic are generated and the intrusion detection system must dynamically collected and analyzed the data produce by the incoming traffic. However in a large dataset not all features contribute to represent the traffic, therefore reducing and selecting a number of adequate features may improve the speed and accuracy of the intrusion detection system. In this study, a feature selection mechanism has been proposed which aims to eliminate non-relevant features as well as identify the features which will contribute to improve the detection rate, based on the score each features have established during the selection process. To achieve that objective, a recursive feature elimination process was employed and associated with a decision tree based classifier and later on, the suitable relevant features were identified. This approach was applied on the NSL-KDD dataset which is an improved version of the previous KDD 1999 Dataset, scikit-learn that is a machine learning library written in python was used in this paper. Using this approach, relevant features were identified inside the dataset and the accuracy rate was improved. These results lend to support the idea that features selection improve significantly the classifier performance. Understanding the factors that help identify relevant features will allow the design of a better intrusion detection system.

  19. PREDICTING THE CONSEQUENCES OF SEAWATER INTRUSION AND PROTECTION PROJECTS

    Institute of Scientific and Technical Information of China (English)

    袁益让; 梁栋; 芮洪兴

    2001-01-01

    The simulation of this process and the effects of protection irojects lays the foundation of its effective control and defence. The mathematical model of the problem and upwind splitting alternating direction method were presented. Using this method, the numerical simulation of seawater intrusion in Laizhou Bay Area of Shandong Provivce was finished. The numerical results turned out to be identical with the real measurements, so the prediction of the consequences of protection projectects is reasonable.

  20. A Novel Approach For Protecting Exposed Intranet From Intrusions

    Directory of Open Access Journals (Sweden)

    K.B.Chandradeep

    2010-07-01

    Full Text Available This paper proposes a novel approach for protecting groups of computers in an intranet from maliciousattacks. The proposed scheme uses a distributed intrusion detection system as the primary source ofsecurity mechanism along with micro-firewalls at the host level to enable dynamic policy update for theintranet as and when the threat pattern changes. The authentication mechanism used for authenticatingthe hosts along with the communication mechanism used for communicating the policy update to thehosts is presented.

  1. Medical image of the week: alpha intrusion into REM sleep

    OpenAIRE

    Shetty S; Le T

    2015-01-01

    A 45-year-old woman with a past medical history of hypertension and chronic headaches was referred to the sleep laboratory for high clinical suspicion for sleep apnea based on a history of snoring, witnessed apnea and excessive daytime sleepiness. An overnight sleep study was performed. Images during N3 Sleep and REM sleep are shown (Figures 1 and 2). Alpha intrusion in delta sleep is seen in patients with fibromyalgia, depression, chronic fatigue syndrome, anxiety disorder, and primary sleep...

  2. Resilient Intrusion Tolerance through Proactive and Reactive Recovery

    OpenAIRE

    Sousa, Paulo; Bessani, Alysson Neves; Correia, Miguel; Neves, Nuno Ferreira; Veríssimo, Paulo

    2007-01-01

    Previous works have studied how to use proactive recovery to build intrusion-tolerant replicated systems that are resilient to any number of faults, as long as recoveries are faster than an upper-bound on fault production assumed at system deployment time. In this work, we propose a complementary approach that combines proactive recovery with services that allow correct replicas to react and recover replicas that they detect or suspect to be compromised. One key feature of our proactive-react...

  3. Intrusion Correlation Using Ontologies and Multi-agent Systems

    Science.gov (United States)

    Isaza, Gustavo; Castillo, Andrés; López, Marcelo; Castillo, Luis; López, Manuel

    This paper proposes an ontology model for representing intrusion detection events and prevention rules, integrating multiagent systems based on unsupervised and supervised techniques for classification, correlation and pattern recognition. The semantic model describes attacks signatures, reaction tasks, axioms with alerts communication and correlation; nevertheless we have developed the prevention architecture integrated with another security tools. This article focuses on the approach to incorporate semantic operations that facilitate alerts correlation process and providing the inference and reasoning to the ontology model.

  4. Vapor intrusion in soils with multimodal pore-size distribution

    OpenAIRE

    Alfaro Soto Miguel; Hung Kiang Chang

    2016-01-01

    The Johnson and Ettinger [1] model and its extensions are at this time the most widely used algorithms for estimating subsurface vapor intrusion into buildings (API [2]). The functions which describe capillary pressure curves are utilized in quantitative analyses, although these are applicable for porous media with a unimodal or lognormal pore-size distribution. However, unaltered soils may have a heterogeneous pore distribution and consequently a multimodal pore-size distribution [3], which ...

  5. Geologic and geophysical investigations of Climax stock intrusive, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1983-12-31

    This document contains three parts of a survey of Climax stock intrusive, Nevada by the US Geological Survey. The first contains the results of a conventional survey of the site and an investigation of rock composition. The second contains the results of a gravity survey and the third contains the results of a magnetic aerial survey. Each of the three documents contains a separate abstract.

  6. Bounded Error Approximation Algorithms for Risk-Based Intrusion Response

    Science.gov (United States)

    2015-09-17

    bipartite graphs. Prior to our work, intrusion response had not been studied within a graph- theoretic framework. Some of our important contributions...include: (a) The partial vertex cover problem for matchings (PVCM) is poly time solvable, if either the vertices or the edges are weighted, but NP- hard , if...WPVCM is NP- hard . This means that partial vertex cover problem is unlikely to be solved exactly in polynomial time for vertex-weighted and edge

  7. Enhancing Battlemind: Preventing PTSD by Coping with Intrusive Thoughts

    Science.gov (United States)

    2015-09-01

    condition [t = -2.15, p = .03; t = -1.93, p = .05, respectively]. D AS S- An xi et y Ra ng e 0- 21 Results Depression, Anxiety, and Stress Scale ( DASS ...and interference) caused by the intrusions. The EIS has demonstrated good internal consistency and excellent test-retest reliability, as well as...PTSD. (32) General Psychological Symptoms. The Depression Anxiety Stress Scales- 21 ( DASS - 21 ) (33) is a 21 -item measure that distinguishes between

  8. Probabilistic risk assessment for six vapour intrusion algorithms

    OpenAIRE

    Provoost, J.; Reijnders, L.; Bronders, J.; Van Keer, I.; Govaerts, S.

    2014-01-01

    A probabilistic assessment with sensitivity analysis using Monte Carlo simulation for six vapour intrusion algorithms, used in various regulatory frameworks for contaminated land management, is presented here. In addition a deterministic approach with default parameter sets is evaluated against observed concentrations for benzene, ethylbenzene and trichloroethylene. The screening-level algorithms are ranked according to accuracy and conservatism in predicting observed soil air and indoor air ...

  9. Decision Cost Feature Weighting and Its Application in Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    QIAN Quan; GENG Huan-tong; WANG Xu-fa

    2004-01-01

    This paper introduces the cost-sensitive feature weighting strategy and its application in intrusion detection.Cost factors and cost matrix are proposed to demonstrate the misclassification cost for IDS.How to get the whole minimal risk, is mainly discussed in this paper in detail.From experiments, it shows that although decision cost based weight learning exists somewhat attack misclassification, it can achieve relatively low misclassification costs on the basis of keeping relatively high rate of recognition precision.

  10. Stratigraphic controls on saltwater intrusion in the Dominguez Gap area of coastal Los Angeles

    Science.gov (United States)

    Edwards, B.D.; Ehman, K.D.; Ponti, D.J.; Reichard, E.G.; Tinsley, J.C.; Rosenbauer, R.J.; Land, M.

    2009-01-01

    The Los Angeles Basin is a densely populated coastal area that significantly depends on groundwater. A part of this groundwater supply is at risk from saltwater intrusion-the impetus for this study. High-resolution seismic-reflection data collected from the Los Angeles-Long Beach Harbor Complex have been combined with borehole geophysical and descriptive geological data from four nearby ??400-m-deep continuously cored wells and with borehole geophysical data from adjacent water and oil wells to characterize the Pliocene to Holocene stratigraphy of the Dominguez Gap coastal aquifer system. The new data are shown as a north-south, two- dimensional, sequence-stratigraphic model that is compared to existing lithostratigraphic models of the Los Angeles Basin in an attempt to better understand pathways of saltwater intrusion into coastal aquifers. Intrusion of saltwater into the coastal aquifer system generally is attributed to over-pumping that caused the hydraulic gradient to reverse during the mid-1920s. Local water managers have used the existing lithostratigraphic model to site closely spaced injection wells of freshwater (barrier projects) attempting to hydraulically control the saltwater intrusion. Improved understanding of the stratigraphic relationships can guide modifications to barrier design that will allow more efficient operation. Allostratigraphic nomenclature is used to define a new sequence-stratigraphic model for the area because the existing lithostratigraphic correlations that have been used to define aquifer systems are shown not to be time-correlative. The youngest sequence, the Holocene Dominguez sequence, contains the Gaspur aquifer at its base. The Gaspur aquifer is intruded with saltwater and consists of essentially flat-lying gravelly sands deposited by the ancestral Los Angeles River as broad channels that occupied a paleovalley incised into the coastal plain during the last glacio-eustatic highstand. The underlying sequences are deformed into

  11. Reduction of saltwater intrusion by modifying hydraulic conductivity

    Science.gov (United States)

    Strack, O. D. L.; Stoeckl, L.; Damm, K.; Houben, G.; Ausk, B. K.; de Lange, W. J.

    2016-09-01

    We present an approach for reducing saltwater intrusion in coastal aquifers by artificially reducing the hydraulic conductivity in the upper part of selected areas by using a precipitate. We apply a previously presented analytical approach to develop formulas useful for the design of artificial barriers. Equations for the location of the tip of the saltwater wedge are presented and verified through a sand-tank experiment. The analysis is capable of computing discharges exactly, but requires the Dupuit-Forchheimer approximation to compute points of the interface between flowing fresh and stationary saltwater. We consider a vertical coastline and boundaries in the freshwater zone of either given discharge or given head. We demonstrate in the paper that reduction of the hydraulic conductivity in the upper part of a coastal aquifer will result in a decrease of saltwater intrusion, and present analytic expressions that can be used for design purposes. The previously presented analytical approach can be applied to design systems to reduce saltwater intrusion caused by pumping inland from the zone that contains saline groundwater.

  12. Internet Intrusion Detection System Service in a Cloud

    Directory of Open Access Journals (Sweden)

    Amirreza Zarrabi

    2012-09-01

    Full Text Available Intrusion Detection Systems (IDS have been used widely to detect malicious behaviors in network communication and hosts. It is defined as a computer network system to collect information on a number of key points, and analyze this information to see whether there are violations of network security policy behavior and signs of attack. IDS aroused the concern of users as an important computer network security technology. In recent times, with the advent of Cloud Computing, the concepts of Software as a Service (SaaS, where vendors provide key software products as services over the internet that can be accessed by users to perform complex tasks, have become increasingly popular. Cloud Computing is a method to increase the capacity or add capabilities dynamically without investing in new infrastructure, training new personnel, or licensing new software. We introduce a Cloud Intrusion Detection System Services (CIDSS which is developed based on Cloud Computing and can make up for the deficiency of traditional intrusion detection, and proved to be great scalable. CIDSS can be utilized to overcome the critical challenge of keeping the client secure from cyber attacks while benefit the features which are presented by Cloud Computing technology.

  13. HYBRID FEATURE SELECTION ALGORITHM FOR INTRUSION DETECTION SYSTEM

    Directory of Open Access Journals (Sweden)

    Seyed Reza Hasani

    2014-01-01

    Full Text Available Network security is a serious global concern. Usefulness Intrusion Detection Systems (IDS are increasing incredibly in Information Security research using Soft computing techniques. In the previous researches having irrelevant and redundant features are recognized causes of increasing the processing speed of evaluating the known intrusive patterns. In addition, an efficient feature selection method eliminates dimension of data and reduce redundancy and ambiguity caused by none important attributes. Therefore, feature selection methods are well-known methods to overcome this problem. There are various approaches being utilized in intrusion detections, they are able to perform their method and relatively they are achieved with some improvements. This work is based on the enhancement of the highest Detection Rate (DR algorithm which is Linear Genetic Programming (LGP reducing the False Alarm Rate (FAR incorporates with Bees Algorithm. Finally, Support Vector Machine (SVM is one of the best candidate solutions to settle IDSs problems. In this study four sample dataset containing 4000 random records are excluded randomly from this dataset for training and testing purposes. Experimental results show that the LGP_BA method improves the accuracy and efficiency compared with the previous related research and the feature subcategory offered by LGP_BA gives a superior representation of data.

  14. Intrusion and extrusion of a liquid on nanostructured surfaces

    Science.gov (United States)

    Amabili, M.; Giacomello, A.; Meloni, S.; Casciola, C. M.

    2017-01-01

    Superhydrophobicity is connected to the presence of gas pockets within surface asperities. Upon increasing the pressure this ‘suspended’ state may collapse, causing the complete wetting of the rough surface. In order to quantitatively characterize this process on nanostructured surfaces, we perform rare-event atomistic simulations at different pressures and for several texture geometries. Such an approach allows us to identify for each pressure the stable and metastable states and the free energy barriers separating them. Results show that, by starting from the superhydrophobic state and increasing the pressure, the suspended state abruptly collapses at a critical intrusion pressure. If the pressure is subsequently decreased, the system remains trapped in the metastable state corresponding to the wet surface. The liquid can be extruded from the nanostructures only at very negative pressures, by reaching the critical extrusion pressure (spinodal for the confined liquid). The intrusion and extrusion curves form a hysteresis cycle determined by the large free energy barriers separating the suspended and wet states. These barriers, which grow very quickly for pressures departing from the intrusion/extrusion pressure, are shown to strongly depend on the texture geometry.

  15. Respon Konsumen pada Mobile Advergames: Intrusiveness dan Irritation

    Directory of Open Access Journals (Sweden)

    Sony Kusumasondjaja

    2016-12-01

    Full Text Available Abstract. Increasing adoption of mobile advergames to deliver marketing messages has not been followed by empirical findings to support its effectiveness. This research attempts to examine the effect of mobile advergames intrusiveness on consumer irritation, attitudes, and purchase intention. This investigation on mobile advergame effectiveness was based on the increasing use of mobile media to deliver marketing messages to consumers from different demographic background. Conceptual framework was developed based on Advertising Avoidance Theory. For data collection, self-administered survey was conducted by adopting purposive sampling involving 213 respondents residing in Surabaya who have had experience in playing mobile game as respondents. Results indicate that intrusiveness positively affects consumer irritation. Consumer irritation negatively affects attitude towards the mobile advergames and attitude towards the advertised product. The better the consumer attitude towards the mobile advergames, the more positive the attitude towards the advertised product. Moreover, the more positive the attitude towards the advertised product, the greater the consumer intention to purchase. Interestingly, consumer attitude toward the mobile advergames has insignificant influence on purchase intention. Findings of the study offer significant contribution to marketing practices using mobile advergames as media placement in their advertising strategy. Keywords: intrusiveness, irritation, mobile advergames, attitude, advertising

  16. Abstracting massive data for lightweight intrusion detection in computer networks

    KAUST Repository

    Wang, Wei

    2016-10-15

    Anomaly intrusion detection in big data environments calls for lightweight models that are able to achieve real-time performance during detection. Abstracting audit data provides a solution to improve the efficiency of data processing in intrusion detection. Data abstraction refers to abstract or extract the most relevant information from the massive dataset. In this work, we propose three strategies of data abstraction, namely, exemplar extraction, attribute selection and attribute abstraction. We first propose an effective method called exemplar extraction to extract representative subsets from the original massive data prior to building the detection models. Two clustering algorithms, Affinity Propagation (AP) and traditional . k-means, are employed to find the exemplars from the audit data. . k-Nearest Neighbor (k-NN), Principal Component Analysis (PCA) and one-class Support Vector Machine (SVM) are used for the detection. We then employ another two strategies, attribute selection and attribute extraction, to abstract audit data for anomaly intrusion detection. Two http streams collected from a real computing environment as well as the KDD\\'99 benchmark data set are used to validate these three strategies of data abstraction. The comprehensive experimental results show that while all the three strategies improve the detection efficiency, the AP-based exemplar extraction achieves the best performance of data abstraction.

  17. Treatment of Intrusive Suicidal Imagery Using Eye Movements

    Directory of Open Access Journals (Sweden)

    Jaël S. van Bentum

    2017-06-01

    Full Text Available Suicide and suicidal behavior are major public health concerns, and affect 3–9% of the population worldwide. Despite increased efforts for national suicide prevention strategies, there are still few effective interventions available for reducing suicide risk. In this article, we describe various theoretical approaches for suicide ideation and behavior, and propose to examine the possible effectiveness of a new and innovative preventive strategy. A model of suicidal intrusion (mental imagery related to suicide, also referred to as suicidal flash-forwards is presented describing one of the assumed mechanisms in the etiology of suicide and the mechanism of therapeutic change. We provide a brief rationale for an Eye Movement Dual Task (EMDT treatment for suicidal intrusions, describing techniques that can be used to target these suicidal mental images and thoughts to reduce overall behavior. Based on the available empirical evidence for the mechanisms of suicidal intrusions, this approach appears to be a promising new treatment to prevent suicidal behavior as it potentially targets one of the linking pins between suicidal ideation and suicidal actions.

  18. Intrusive Method for Uncertainty Quantification in a Multiphase Flow Solver

    Science.gov (United States)

    Turnquist, Brian; Owkes, Mark

    2016-11-01

    Uncertainty quantification (UQ) is a necessary, interesting, and often neglected aspect of fluid flow simulations. To determine the significance of uncertain initial and boundary conditions, a multiphase flow solver is being created which extends a single phase, intrusive, polynomial chaos scheme into multiphase flows. Reliably estimating the impact of input uncertainty on design criteria can help identify and minimize unwanted variability in critical areas, and has the potential to help advance knowledge in atomizing jets, jet engines, pharmaceuticals, and food processing. Use of an intrusive polynomial chaos method has been shown to significantly reduce computational cost over non-intrusive collocation methods such as Monte-Carlo. This method requires transforming the model equations into a weak form through substitution of stochastic (random) variables. Ultimately, the model deploys a stochastic Navier Stokes equation, a stochastic conservative level set approach including reinitialization, as well as stochastic normals and curvature. By implementing these approaches together in one framework, basic problems may be investigated which shed light on model expansion, uncertainty theory, and fluid flow in general. NSF Grant Number 1511325.

  19. Numerical Continuation Methods for Intrusive Uncertainty Quantification Studies

    Energy Technology Data Exchange (ETDEWEB)

    Safta, Cosmin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Najm, Habib N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Phipps, Eric Todd [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Rigorous modeling of engineering systems relies on efficient propagation of uncertainty from input parameters to model outputs. In recent years, there has been substantial development of probabilistic polynomial chaos (PC) Uncertainty Quantification (UQ) methods, enabling studies in expensive computational models. One approach, termed ”intrusive”, involving reformulation of the governing equations, has been found to have superior computational performance compared to non-intrusive sampling-based methods in relevant large-scale problems, particularly in the context of emerging architectures. However, the utility of intrusive methods has been severely limited due to detrimental numerical instabilities associated with strong nonlinear physics. Previous methods for stabilizing these constructions tend to add unacceptably high computational costs, particularly in problems with many uncertain parameters. In order to address these challenges, we propose to adapt and improve numerical continuation methods for the robust time integration of intrusive PC system dynamics. We propose adaptive methods, starting with a small uncertainty for which the model has stable behavior and gradually moving to larger uncertainty where the instabilities are rampant, in a manner that provides a suitable solution.

  20. Security Policy Based on Firewall and Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    Hemdeep Kaur Bimbraw

    2014-11-01

    Full Text Available Firewalls are usually the first component of network security. They separate networks in different security levels by utilizing network access control policies. The major function of the firewall is to protect the private network from non-legitimate traffic. The main purpose of a firewall system is to control access to or from a protected network. It implements a network access policy by forcing connections to pass through the firewall, where they can be examined and evaluated. Intrusion detection is the process of monitoring and searching networks of computers and systems for security policy violations. Intrusion Detection Systems (IDSs are software or hardware products that automate this monitoring and analysis process. An IDS inspects all inbound and outbound network activity, system logs and events, and identifies suspicious patterns or events that may indicate a network or system attack from someone attempting to break into or compromise a system. The network security in today’s world is a major concern because of increasing threats from malicious users. Therefore, designing a correct network security policy is a challenging task. To design filtering rules to formulate a sound firewall security policy and implement intrusion detection system to capture network packets and detect attacks to fulfill this gap

  1. Hybrid Intrusion Detection Using Ensemble of Classification Methods

    Directory of Open Access Journals (Sweden)

    M.Govindarajan

    2014-01-01

    Full Text Available One of the major developments in machine learning in the past decade is the ensemble method, which finds highly accurate classifier by combining many moderately accurate component classifiers. In this research work, new ensemble classification methods are proposed for homogeneous ensemble classifiers using bagging and heterogeneous ensemble classifiers using arcing classifier and their performances are analyzed in terms of accuracy. A Classifier ensemble is designed using Radial Basis Function (RBF and Support Vector Machine (SVM as base classifiers. The feasibility and the benefits of the proposed approaches are demonstrated by the means of real and benchmark data sets of intrusion detection. The main originality of the proposed approach is based on three main parts: preprocessing phase, classification phase and combining phase. A wide range of comparative experiments are conducted for real and benchmark data sets of intrusion detection. The accuracy of base classifiers is compared with homogeneous and heterogeneous models for data mining problem. The proposed ensemble methods provide significant improvement of accuracy compared to individual classifiers and also heterogeneous models exhibit better results than homogeneous models for real and benchmark data sets of intrusion detection.

  2. Detection and Protection Against Intrusions on Smart Grid Systems

    Directory of Open Access Journals (Sweden)

    Ata Arvani

    2015-05-01

    Full Text Available The wide area monitoring of power systems is implemented at a central control center to coordinate the actions of local controllers. Phasor measurement units (PMUs are used for the collection of data in real time for the smart grid energy systems. Intrusion detection and cyber security of network are important requirements for maintaining the integrity of wide area monitoring systems. The intrusion detection methods analyze the measurement data to detect any possible cyber attacks on the operation of smart grid systems. In this paper, the model-based and signal-based intrusion detection methods are investigated to detect the presence of malicious data. The chi-square test and discrete wavelet transform (DWT have been used for anomaly-based detection. The false data injection attack (FDIA can be detected using measurement residual. If the measurement residual is larger than expected detection threshold, then an alarm is triggered and bad data can be identified. Avoiding such alarms in the residual test is referred to as stealth attack. There are two protection strategies for stealth attack: (1 Select a subset of meters to be protected from the attacker (2 Place secure phasor measurement units in the power grid. An IEEE 14-bus system is simulated using real time digital simulator (RTDS hardware platform for implementing attack and detection schemes.

  3. Active Low Intrusion Hybrid Monitor for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Marlon Navia

    2015-09-01

    Full Text Available Several systems have been proposed to monitor wireless sensor networks (WSN. These systems may be active (causing a high degree of intrusion or passive (low observability inside the nodes. This paper presents the implementation of an active hybrid (hardware and software monitor with low intrusion. It is based on the addition to the sensor node of a monitor node (hardware part which, through a standard interface, is able to receive the monitoring information sent by a piece of software executed in the sensor node. The intrusion on time, code, and energy caused in the sensor nodes by the monitor is evaluated as a function of data size and the interface used. Then different interfaces, commonly available in sensor nodes, are evaluated: serial transmission (USART, serial peripheral interface (SPI, and parallel. The proposed hybrid monitor provides highly detailed information, barely disturbed by the measurement tool (interference, about the behavior of the WSN that may be used to evaluate many properties such as performance, dependability, security, etc. Monitor nodes are self-powered and may be removed after the monitoring campaign to be reused in other campaigns and/or WSNs. No other hardware-independent monitoring platforms with such low interference have been found in the literature.

  4. Reconfigurable Hardware Architecture for Network Intrusion Detection System

    Directory of Open Access Journals (Sweden)

    A. Kaleel Rahuman

    2012-01-01

    Full Text Available Intrusion rule processing in reconfigurable hardware enables intrusion detection and prevention. The use of reconfigurable hardware for network security applications has great strides as Field Programmable Gate Array (FPGA devices have provided larger and faster resources. This proposes architecture called “BV-TCAM” is presented, which is implemented for an FPGA-based Network Intrusion Detection Systems (NIDS. The BV-TCAM architecture combines the Ternary Content Addressable Memory (TCAM and Bit Vector (BV algorithm to effectively compress the data representation and throughput. A tree bitmap implementation of the BV algorithm is used for source and destination port lookup while a TCAM performs lookup for other header fields, which can be represented as a prefix or exact value. With the aid of small embedded TCAM, packet classification can be implemented in relatively small part of the available logic of an FPGA. The BV-TCAM architecture has been modelled by VHDL. Simulations were performed by MODELSIM. This architecture have to be synthesized and implement our design using Xilinx FPGA device."

  5. Temporal associations and prior-list intrusions in free recall.

    Science.gov (United States)

    Zaromb, Franklin M; Howard, Marc W; Dolan, Emily D; Sirotin, Yevgeniy B; Tully, Michele; Wingfield, Arthur; Kahana, Michael J

    2006-07-01

    When asked to recall the words from a just-presented target list, subjects occasionally recall words that were not on the list. These intrusions either appeared on earlier lists (prior-list intrusions, or PLIs) or had not appeared over the course of the experiment (extra-list intrusions). The authors examined the factors that elicit PLIs in free recall. A reanalysis of earlier studies revealed that PLIs tend to come from semantic associates as well as from recently studied lists, with the rate of PLIs decreasing sharply with list recency. The authors report 3 new experiments in which some items in a given list also appeared on earlier lists. Although repetition enhanced recall of list items, subjects were significantly more likely to make PLIs following the recall of repeated items, suggesting that temporal associations formed in earlier lists can induce recall errors. The authors interpret this finding as evidence for the interacting roles of associative and contextual retrieval processes in recall. Although contextual information helps to focus recall on words in the target list, it does not form an impermeable boundary between current- and prior-list experiences. Copyright 2006 APA, all rights reserved.

  6. An Automata Based Intrusion Detection Method for Internet of Things

    Directory of Open Access Journals (Sweden)

    Yulong Fu

    2017-01-01

    Full Text Available Internet of Things (IoT transforms network communication to Machine-to-Machine (M2M basis and provides open access and new services to citizens and companies. It extends the border of Internet and will be developed as one part of the future 5G networks. However, as the resources of IoT’s front devices are constrained, many security mechanisms are hard to be implemented to protect the IoT networks. Intrusion detection system (IDS is an efficient technique that can be used to detect the attackers when cryptography is broken, and it can be used to enforce the security of IoT networks. In this article, we analyzed the intrusion detection requirements of IoT networks and then proposed a uniform intrusion detection method for the vast heterogeneous IoT networks based on an automata model. The proposed method can detect and report the possible IoT attacks with three types: jam-attack, false-attack, and reply-attack automatically. We also design an experiment to verify the proposed IDS method and examine the attack of RADIUS application.

  7. Active Low Intrusion Hybrid Monitor for Wireless Sensor Networks.

    Science.gov (United States)

    Navia, Marlon; Campelo, Jose C; Bonastre, Alberto; Ors, Rafael; Capella, Juan V; Serrano, Juan J

    2015-09-18

    Several systems have been proposed to monitor wireless sensor networks (WSN). These systems may be active (causing a high degree of intrusion) or passive (low observability inside the nodes). This paper presents the implementation of an active hybrid (hardware and software) monitor with low intrusion. It is based on the addition to the sensor node of a monitor node (hardware part) which, through a standard interface, is able to receive the monitoring information sent by a piece of software executed in the sensor node. The intrusion on time, code, and energy caused in the sensor nodes by the monitor is evaluated as a function of data size and the interface used. Then different interfaces, commonly available in sensor nodes, are evaluated: serial transmission (USART), serial peripheral interface (SPI), and parallel. The proposed hybrid monitor provides highly detailed information, barely disturbed by the measurement tool (interference), about the behavior of the WSN that may be used to evaluate many properties such as performance, dependability, security, etc. Monitor nodes are self-powered and may be removed after the monitoring campaign to be reused in other campaigns and/or WSNs. No other hardware-independent monitoring platforms with such low interference have been found in the literature.

  8. Influence of an igneous intrusion on the inorganic geochemistry of a bituminous coal from Pitkin County, Colorado

    Science.gov (United States)

    Finkelman, R.B.; Bostick, N.H.; Dulong, F.T.; Senftle, F.E.; Thorpe, A.N.

    1998-01-01

    Although the effects of igneous dikes on the organic matter in coal have been observed at many localities there is virtually no information on the effects of the intrusions of the inorganic constituents in the coal. Such a study may help to elucidate the behavior of trace elements during in situ gasification of coal and may provide insights into the resources potential for coal and coke affected by the intrusion. To determine the effects of an igneous intrusion on the inorganic chemistry of a coal we used a series of 11 samples of coal and natural coke that had been collected at intervals from 3 to 106 cm from a dike that intruded the bituminous Dutch Creek coal in Pitkin, CO. The samples were chemically analyzed for 66 elements. SEM-EDX and X-ray diffraction analysis were performed on selected samples. Volatile elements such as F, Cl, Hg, and Se are not depleted in the samples (coke and coal) nearest the dike that were exposed to the highest temperatures. Their presence in these samples is likely due to secondary enrichment following volatilization of the elements inherent in the coal. Equilibration with ground water may account for the uniform distribution of Na, B, and Cl. High concentrations of Ca, Mg, Fe, Mn, Sr, and CO2 in the coke region are attributed to the reaction of CO and CO2 generated during the coking of the coal with fluids from the intrusion, resulting in the precipitation of carbonates. Similarly, precipitation of sulfide minerals in the coke zone may account for the relatively high concentrations of Ag, Hg, Cu, Zn, and Fe. Most elements are concentrated at the juncture of the fluidized coke and the thermally metamorphosed coal. Many of the elements enriched in this region (for example, Ga, Ge, Mo, Rb, U, La, Ce, Al, K, and Si) may have been adsorbed on either the clays or the organic matter or on both.Although the effects of igneous dikes on the organic matter in coal have been observed at many localities there is virtually no information on the

  9. A felsic MASH zone of crustal magmas - Feedback between granite magma intrusion and in situ crustal anatexis

    Science.gov (United States)

    Schwindinger, Martin; Weinberg, Roberto F.

    2017-07-01

    Magma mixing and mingling are described from different tectonic environments and are key mechanisms in the evolution of granitoids. The literature focuses on the interaction between mafic and felsic magmas with only limited research on the interaction between similar magmas. Here, we investigate instead hybridization processes between felsic magmas formed during the 500 Ma Delamerian Orogeny on the south coast of Kangaroo Island. Field relations suggest that a coarse, megacrystic granite intruded and interacted with a fine-grained diatexite that resulted from combined muscovite dehydration and water-fluxed melting of Kanmantoo Group turbidites. The two magmas hybridized during syn-magmatic deformation, explaining the complexity of relationships and variability of granitoids exposed. We suggest that granite intrusion enhanced melting of the turbidites by bringing in heat and H2O. With rising melt fraction, intrusive magmas became increasingly unable to traverse the partially molten terrane, creating a positive feedback between intrusion and anatexis. This feedback loop generated the exposed mid-crustal zone where magmas mixed and homogenized. Thus, the outcrops on Kangaroo Island represent a crustal and felsic melting-assimilation-storage-homogenization (felsic MASH) zone where, instead of having direct mantle magma involvement, as originally proposed, these processes developed in a purely crustal environment formed by felsic magmas.

  10. Use of major ions to evaluate the hydrogeochemistry of groundwater influenced by reclamation and seawater intrusion, West Nile Delta, Egypt.

    Science.gov (United States)

    Salem, Zenhom El-Said; Osman, Osman M

    2017-02-01

    The aim of this research is to evaluate the groundwater geochemistry in western Nile Delta area as an example of an aquifer influenced by reclamation and seawater intrusion. To conduct this study, 63 groundwater samples and one surface water sample from El Nubaria Canal were collected. To estimate the origin of dissolved ions and the geochemical processes influencing this groundwater, integration between land use change, pedological, hydrogeological, hydrogeochemical, and statistical approaches was considered. Results suggest that the groundwater flow regime changed from northeast and southwest directions around El Nubaria canal before 1966 to northern and northeastern directions due to newly constructed channel network. Soil salinity and mineral contents, seepage from irrigation canal, and seawater intrusion are the main factors controlling the groundwater chemistry. Statistically, the groundwater samples were classified into eight groups, one to four for the deep groundwater and five to eight for the shallow groundwater. The deep groundwater is characterized by two groups of chemicals (SO4-HCO3-Mg-Ca-K and Cl-Na), while the shallow groundwater groups of chemicals are Na-Cl-SO4 and K-HCO3-Ca-Mg. Both shallow groundwater and deep groundwater are mostly saturated with respect to carbonate minerals and undersaturated with respect to chloride minerals. Sulfate minerals are above the saturation limit in the shallow groundwater, but in the deep samples, these minerals are under the saturation limit. Ion exchange, carbonate production, mineral precipitation, and seawater intrusion are the geochemical processes governing the groundwater chemistry in the study area.

  11. Basement influences on dolomite-hosted vertical sedimentary intrusions in marine erg-margin deposits from the Pennsylvanian of Northern Wyoming (USA)

    Science.gov (United States)

    Blanchard, Sébastien; Frank, Tracy D.; Fielding, Christopher R.

    2016-06-01

    Understanding soft-sediment deformation structures and their triggers can help in assessing the influence of tectonics, climate, and diagenesis on the stratigraphic record. Such features commonly record processes that would not otherwise be preserved. The description of soft-sediment deformation in Pennsylvanian deposits of the western United States, characterized by orbitally driven alternations between eolian sandstones, marine dolomites, and shales, has been limited to contorted cross-beds. We document discordant, sheet-like sedimentary intrusions in three marine intervals over a 45-km-wide area. Intrusions consist of very well to moderately cemented, very fine to fine-grained quartz sandstone. Body widths range from 5 to 50 cm, and heights up to 2 m. The orientations of 103 vertical bodies were measured. Based on upward- and downward-tapering, and the presence of deformed, microfractured fragments of host rocks, these intrusions are interpreted to result from seismically induced fluidization of water-saturated sands. Their sheet-like morphology indicates injection through fractures. Two predominant directions (WNW-ESE and N-S) were recognized and interpreted as pre-injection fracture sets. Folding of surrounding layers around the intrusions suggests negligible compaction prior to injection, indicating penecontemporaneous or shallow burial fluidization. The intraplate location of Wyoming implies that seismicity did not originate at a plate boundary. The area within which intrusions are found is crossed by a zone characterized by localized development of thick eolian stories at the top of the formation, interpreted to reflect the rejuvenation of a basement lineament. The seismically active character of lineaments may explain overpressure and fluidization, substantiating the notion that Precambrian structures repeatedly affected Phanerozoic sedimentation. Similar intrusive features may be wrongly identified or overlooked in deposits of arid environments, but their

  12. Assessing impacts of climate change, sea level rise, and drainage canals on saltwater intrusion to coastal aquifer

    Directory of Open Access Journals (Sweden)

    P. Rasmussen

    2012-07-01

    Full Text Available Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. Agricultural land dominates the western and central parts of the island, which geologically are developed as push moraine hills and a former lagoon (later wetland area behind barrier islands to the east. The low-lying central area of the island was extensively drained and reclaimed during the second half of the 19th century. Summer cottages along the beach on the former barrier islands dominate the eastern part of the island. The main water abstraction is for holiday cottages during the summer period (June–August. The water is abstracted from 11 wells drilled to a depth of around 20 m in the upper 5–10 m of a confined chalk aquifer. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater–sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise do not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area below which the sea is

  13. Evaluation of the effects of sea-level change and coastal canal management on saltwater intrusion in the Biscayne aquifer of south Florida, USA

    Science.gov (United States)

    Hughes, J. D.; Sifuentes, D. F.; White, J.

    2015-12-01

    Sea-level increases are expected to have an effect on the position of the freshwater-saltwater interface in the Biscayne aquifer in south Florida as a result of the low topographic relief of the area and high rates of groundwater withdrawal from the aquifer. To study the effects that future sea-level increases will have on saltwater intrusion in the Biscayne aquifer in Broward County, Florida, a three-dimensional, variable-density, groundwater-flow and transport model was developed. The model was calibrated to observed groundwater heads and chloride concentrations for a 62-year period that includes historic increases in sea level, development of a surface-water management system to control flooding, and increases in groundwater withdrawals as the area transitioned from agricultural to urban land uses. Sensitivity analyses indicate that downward leakage of saltwater from coastal canals and creeks was the primary source of saltwater to the Biscayne aquifer during the last 62-years in areas where the surface-water system is not actively managed and is tidally influenced. In areas removed from the coastal canals and creeks or under active surface-water management, historic groundwater withdrawals were the primary cause of saltwater intrusion into the aquifer. Simulation of future conditions suggests that possible increases in sea level will result in additional saltwater intrusion. Model scenarios suggest that additional saltwater intrusion will be greatest in areas where coastal canals and creeks were historically the primary source of seawater. Future saltwater intrusion in those areas, however, may be reduced by relocation of salinity-control structures.

  14. Identifying Stratospheric Air Intrusions and Associated Hurricane-Force Wind Events over the North Pacific Ocean

    Science.gov (United States)

    Malloy, Kelsey; Folmer, Michael J.; Phillips, Joseph; Sienkiewicz, Joseph M.; Berndt, Emily

    2017-01-01

    Motivation: Ocean data is sparse: reliance on satellite imagery for marine forecasting; Ocean Prediction Center (OPC) –“mariner’s weather lifeline”. Responsible for: Pacific, Atlantic, Pacific Alaska surface analyses –24, 48, 96 hrs.; Wind & wave analyses –24, 48, 96 hrs.; Issue warnings, make decisions, Geostationary Operational Environmental Satellite –R Series (now GOES-16), Compared to the old GOES: 3 times spectral resolution, 4 times spatial resolution, 5 times faster coverage; Comparable to Japanese Meteorological Agency’s Himawari-8, used a lot throughout this research. Research Question: How can integrating satellite data imagery and derived products help forecasters improve prognosis of rapid cyclogenesis and hurricane-force wind events? Phase I –Identifying stratospheric air intrusions: Water Vapor –6.2, 6.9, 7.3 micron channels; Airmass RGB Product; AIRS, IASI, NUCAPS total column ozone and ozone anomaly; ASCAT (A/B) and AMSR-2 wind data.

  15. Petrogenesis of permian sulfide-bearing mafic-ultramafic intrusions insoutheast Chinese Altay and east Tianshan, NW China

    OpenAIRE

    Gao, Jianfeng; 高剑峰

    2012-01-01

    The Central Asia Orogenic Belt is one of the largest accretionary orogenic belts in the world. In this belt, many sulfide‐bearing mafic‐ultramafic intrusions occur along faults, including the Kalatongke complex in southeast Chinese Altay and the Huangshandong intrusion in east Tianshan. The Kalatongke complex is a composite body including ~308Ma dioritic intrusion and 287Ma sulfide‐bearing mafic intrusion. The dioritic intrusion consists of biotite‐hornblende gabbro, diorite and quartz d...

  16. Application of time-domain electromagnetic method in mapping saltwater intrusion of a coastal alluvial aquifer, North Oman

    Science.gov (United States)

    El-Kaliouby, Hesham; Abdalla, Osman

    2015-04-01

    One-third of the population of Oman depends on the groundwater extracted from the alluvium deposits located along the coast of the Gulf of Oman. However, groundwater depletion and seawater intrusion constitute major challenges along the coastal water accumulations in Oman. The objective of this study is to locate the extent of seawater intrusion and to map the shallow alluvial aquifer in the region, where water accumulates from the rain or the flooding at AlKhod dam. In order to assess the effect of groundwater infiltration, which recharges the aquifer and fights the seawater invasion, a quantitative approach for the groundwater quality and distribution is required to provide reasonable knowledge on the spatial distribution of the aquifers, their thickness and the type of sediments. When groundwater wells and their subsurface geologic and electrical logs are not available or not deep enough, surface geophysical surveys can be considered due to their low cost and short acquisition time. The application of time-domain electromagnetic (TDEM) method in Al-Khod area, Oman has proven to be a successful tool in mapping the fresh/saline water interface and for locating the depth of fresh water aquifer. The depths and inland extents of the saline zone were mapped along three N-S TDEM profiles. The depths to the freshwater table and saline interface calculated from TDEM closely match the available well data.

  17. Water

    Science.gov (United States)

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  18. Assessing impacts of climate change, sea level rise, and drainage canals on saltwater intrusion to coastal aquifer

    Directory of Open Access Journals (Sweden)

    P. Rasmussen

    2013-01-01

    Full Text Available Groundwater abstraction from coastal aquifers is vulnerable to climate change and sea level rise because both may potentially impact saltwater intrusion and hence groundwater quality depending on the hydrogeological setting. In the present study the impacts of sea level rise and changes in groundwater recharge are quantified for an island located in the Western Baltic Sea. The low-lying central area of the investigated part of the island was extensively drained and reclaimed during the second half of the 19th century by a system of artificial drainage canals that significantly affects the flow dynamics of the area. The drinking water, mainly for summer cottages, is abstracted from 11 wells drilled to a depth of around 20 m into the upper 5–10 m of a confined chalk aquifer, and the total pumping is only 5–6% of the drainage pumping. Increasing chloride concentrations have been observed in several abstraction wells and in some cases the WHO drinking water standard has been exceeded. Using the modeling package MODFLOW/MT3D/SEAWAT the historical, present and future freshwater-sea water distribution is simulated. The model is calibrated against hydraulic head observations and validated against geochemical and geophysical data from new investigation wells, including borehole logs, and from an airborne transient electromagnetic survey. The impact of climate changes on saltwater intrusion is found to be sensitive to the boundary conditions of the investigated system. For the flux-controlled aquifer to the west of the drained area only changes in groundwater recharge impacts the freshwater–sea water interface whereas sea level rise does not result in increasing sea water intrusion. However, on the barrier islands to the east of the reclaimed area, below which the sea is hydraulically connected to the drainage canals, and the boundary of the flow system therefore controlled, the projected changes in sea level, groundwater recharge and stage of the

  19. The radiative response of the lower troposphere to moisture intrusions into the Arctic

    Science.gov (United States)

    Johansson, Erik; Devasthale, Abhay; Tjernström, Michael; Ekman, Annica M. L.; L'Ecuyer, Tristan

    2016-04-01

    Water vapour (WV) transport into the Arctic occurs on daily to seasonal time scales and affects the Arctic atmosphere and surface energy balance in a number of ways. Extreme transport events, hereafter referred to as WV intrusions (WVI), account for a significant fraction of the total transport of water vapour into the Arctic. Considering their overall impact on the total moisture transport, WVIs are expected to strongly influence the radiative properties of the lower troposphere. Being a potent greenhouse gas, WV has a warming effect on the surface via its longwave forcing. As a result, WVIs have potential to warm the sea-ice surface and depending on their strength and degree of persistence, precondition accelerated melting of sea ice in subsequent months following the intrusion WVIs also affect the prevalent thermodynamical characteristics of the lowermost troposphere such as the presence of temperature and humidity inversions. They can further modulate cloud formation processes by changing the local thermodynamics. Characterizing the response of the lower troposphere to WVIs is therefore important, mainly to improve our understanding of the processes, affecting, air-sea-ice interactions. In this context, the aim of the present study is to provide observationally based insights into how the lower troposphere radiatively responds to WVIs, defined as events that exceed 90-percentile value of the poleward meridional moisture flux across 70° N. Using the combined lidar and radar (CloudSat+CALIPSO) data from the A-Train constellation of satellites from 2006 through 2010 together with data from AMSR-E, AIRS and MODIS, we examine the dominant circulation patterns that favour WVI and the surface response to WVI. We further quantify changes in cloudiness and cloud radiative effects during WVI.

  20. Estimating salinity intrusion effects due to climate change on the Lower Savannah River Estuary

    Science.gov (United States)

    Conrads, Paul A.; Roehl, Edwin A.; Daamen, Ruby C.; Cook, John B.; Sexton, Charles T.; Tufford, Daniel L.; Carbone, Gregory J.; Dow, Kristin

    2010-01-01

    The ability of water-resource managers to adapt to future climatic change is especially challenging in coastal regions of the world. The East Coast of the United States falls into this category given the high number of people living along the Atlantic seaboard and the added strain on resources as populations continue to increase, particularly in the Southeast. Increased temperatures, changes in regional precipitation regimes, and potential increased sea level may have a great impact on existing hydrological systems in the region. The Savannah River originates at the confluence of the Seneca and Tugaloo Rivers, near Hartwell, Ga., and forms the state boundary between South Carolina and Georgia. The J. Strom Thurmond Dam and Lake, located 238 miles upstream from the Atlantic Ocean, is responsible for most of the flow regulation that affects the Savannah River from Augusta, Ga., to the coast. The Savannah Harbor experiences semi-diurnal tides of two low and two high tides in a 24.8-hour period with pronounced differences in tidal range between neap and spring tides occurring on a 14-day and 28-day lunar cycle. Salinity intrusion results from the interaction of three principal forces - streamflow, mean tidal water levels, and tidal range. To analyze, model, and simulate hydrodynamic behaviors at critical coastal streamgages in the Lower Savannah River Estuary, data-mining techniques were applied to over 15 years of hourly streamflow, coastal water-quality, and water-level data. Artificial neural network (ANN) models were trained to learn the variable interactions that cause salinity intrusions. Streamflow data from the 9,850 square-mile Savannah River Basin were input into the model as time-delayed variables. Tidal inputs to the models were obtained by decomposing tidal water-level data into a “periodic” signal of tidal range and a “chaotic” signal of mean water levels. The ANN models were able to convincingly reproduce historical behaviors and generate

  1. Evolution of the bentonite barrier under glacial meltwater intrusion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, T.; Bouby, M. [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Blechschmidt, I. [NAGRA National Cooperation Disposal Radioactive Waste, Wettingen (Switzerland); and others

    2015-07-01

    Recent safety assessments for repository concepts that combine a clay engineered barrier system (EBS) with a fractured rock have shown that melt water intrusion may have a direct impact on the EBS barrier function in two aspects: - Generation of colloids may degrade the engineered barrier - Colloid transport of radionuclides may reduce the efficiency of the natural barrier The studies presented here are performed in the framework of the Federal Ministry of Economic Affairs and Energy (BMWi) KIT/GRS project KOLLORADO-e, the EU collaborative project CP BELBaR (www.skb.se/belbar) and especially within the Colloid Formation and Migration (CFM) project at the Grimsel Test Site, GTS (www.grimsel.com). Key research areas are (a) the erosion of the bentonite buffer, (b) clay colloid stability and (c) colloid-radionuclide- host rock surface interactions. Concerning bentonite buffer integrity parameters like the bentonite type, Na-/Ca-exchangeable cation ratio, compaction density, role of accessory minerals, the fracture aperture size and groundwater chemistry and flow velocity are investigated in order to identify controlling factors, understand the main mechanisms of erosion from the bentonite surface and to quantify the extent of the possible erosion under these different conditions. Clay colloid stability studies are performed under different geochemical conditions. The main objective is to answer the question if colloids formed at the near/far field interface would be stable only if favourable conditions exist and therefore their relevance for radionuclide transport will be strongly dependent on the local geochemical conditions (inorganic cations Na{sup +}, Ca{sup 2+}, Mg{sup 2+}, Al{sup 3+} and organic complexing agents). Finally, the interaction between colloids and radionuclides and the host rock is intensively investigated in order to answer the question, how colloid mobility may be affected by the composition of the host rock, surface roughness and the mechanism of

  2. Groundwater level changes in a deep well in response to a magma intrusion event on Kilauea Volcano, Hawai'i

    Science.gov (United States)

    Hurwitz, S.; Johnston, M.J.S.

    2003-01-01

    On May 21, 2001, an abrupt inflation of Kilauea Volcano's summit induced a rapid and large increase in compressional strain, with a maximum of 2 ??strain recorded by a borehole dilatometer. Water level (pressure) simultaneously dropped by 6 cm. This mode of water level change (drop) is in contrast to that expected for compressional strain from poroelastic theory, and therefore it is proposed that the stress applied by the intrusion has caused opening of fractures or interflows that drained water out of the well. Upon relaxation of the stress recorded by the dilatometer, water levels have recovered at a similar rate. The proposed model has implications for the analysis of ground surface deformation and for mechanisms that trigger phreatomagmatic eruptions.

  3. Water

    Science.gov (United States)

    ... Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir For information about lead in water in Flint, MI, please visit http://www.phe. ...

  4. Computational benefits using artificial intelligent methodologies for the solution of an environmental design problem: saltwater intrusion.

    Science.gov (United States)

    Papadopoulou, Maria P; Nikolos, Ioannis K; Karatzas, George P

    2010-01-01

    Artificial Neural Networks (ANNs) comprise a powerful tool to approximate the complicated behavior and response of physical systems allowing considerable reduction in computation time during time-consuming optimization runs. In this work, a Radial Basis Function Artificial Neural Network (RBFN) is combined with a Differential Evolution (DE) algorithm to solve a water resources management problem, using an optimization procedure. The objective of the optimization scheme is to cover the daily water demand on the coastal aquifer east of the city of Heraklion, Crete, without reducing the subsurface water quality due to seawater intrusion. The RBFN is utilized as an on-line surrogate model to approximate the behavior of the aquifer and to replace some of the costly evaluations of an accurate numerical simulation model which solves the subsurface water flow differential equations. The RBFN is used as a local approximation model in such a way as to maintain the robustness of the DE algorithm. The results of this procedure are compared to the corresponding results obtained by using the Simplex method and by using the DE procedure without the surrogate model. As it is demonstrated, the use of the surrogate model accelerates the convergence of the DE optimization procedure and additionally provides a better solution at the same number of exact evaluations, compared to the original DE algorithm.

  5. A Comprehensive Study on Classification of Passive Intrusion and Extrusion Detection System

    Directory of Open Access Journals (Sweden)

    A.Kalaivani

    2013-05-01

    Full Text Available Cyber criminals compromise Integrity, Availability and Confidentiality of network resources in cyber space and cause remote class intrusions such as U2R, R2L, DoS and probe/scan system attacks .To handle these intrusions, Cyber Security uses three audit and monitoring systems namely Intrusion Prevention Systems (IPS, Intrusion Detection Systems (IDS. Intrusion Detection System (IDS monitors only inbound traffic which is insufficient to prevent botnet systems. A system to monitor outbound traffic is named as Extrusion Detection System (EDS. Therefore a hybrid system should be designed to handle both inbound and outbound traffic. Due to the increased false alarms preventive systems do not suite to an organizational network. The goal of this paper is to devise a taxonomy for cyber security and study the existing methods of Intrusion and Extrusion Detection systems based on three primary characteristics. The metrics used to evaluate IDS and EDS are also presented.

  6. Provide a model to improve the performance of intrusion detection systems in the cloud

    Directory of Open Access Journals (Sweden)

    Foroogh Sedighi

    2016-12-01

    Full Text Available High availability of tools and service providers in cloud computing and the fact that cloud computing services are provided by internet and deal with public, have caused important challenges for new computing model. Cloud computing faces problems and challenges such as user privacy, data security, data ownership, availability of services, and recovery after breaking down, performance, scalability, programmability. So far, many different methods are presented for detection of intrusion in cloud computing. There are two important factors that differentarticlesand researches are presented based on them. These factors are location of establishing intrusion detection systems in cloud computing systems and also algorithms that are used in intrusion detection. Their final goal is maximum coverage of intrusions, increasing the speed and accuracy of intrusion detection, and decreasing of wrong alarms. Our goal in this article is to increase intrusion detection in cloud computing and decrease the rate of generatingfalsealarmsby presenting a combined method.

  7. Analysis of Fuzzy Logic Based Intrusion Detection Systems in Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    A. Chaudhary

    2014-01-01

    Full Text Available Due to the advancement in wireless technologies, many of new paradigms have opened for communications. Among these technologies, mobile ad hoc networks play a prominent role for providing communication in many areas because of its independent nature of predefined infrastructure. But in terms of security, these networks are more vulnerable than the conventional networks because firewall and gateway based security mechanisms cannot be applied on it. That’s why intrusion detection systems are used as keystone in these networks. Many number of intrusion detection systems have been discovered to handle the uncertain activity in mobile ad hoc networks. This paper emphasized on proposed fuzzy based intrusion detection systems in mobile ad hoc networks and presented their effectiveness to identify the intrusions. This paper also examines the drawbacks of fuzzy based intrusion detection systems and discussed the future directions in the field of intrusion detection for mobile ad hoc networks.

  8. Seawater intrusion barrier and artificial recharge in the deltaic Llobregat aquifer (Barcelona, Spain); La barrera hidraulica contra la intrusion marina y la recarga artificial en el acuifero del Llobregat (Barcelona, Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno Gobern, F.; Ninerola Pla, J. M.; Armenter Ferrando, J. L.; Molinero Huguet, J.

    2009-07-01

    The main aquifer of the Llobregat Delta (Barcelona, Spain) is affected by seawater intrusion processes since 1970. The Catalan Water Agency is currently promoting several actions of enhanced aquifer recharge, including the construction of a positive hydraulic barrier in order to stop the advance of the seawater intrusion. Such a positive hydraulic barrier works by injecting reclaimed water in 14 wells. This is the first time that a project of this type is performed in Spain, and it is also pioneer in Europe. The positive hydraulic barrier produces the rise of the groundwater head near the coast and avoids seawater penetration inland. The injected reclaimed water comes from the WWTP of the Baix Llobregat after passing through several treatments (ultrafiltration, osmosis and disinfection). The pilot phase of the project has been working during the last 2 years, showing highly positive results. Substantial improvement of the groundwater quality has been observed in wells surrounding the injection points and no clogging has been appeared. The second phase of the project is currently under construction. (Author) 13 refs.

  9. Multi-Objective Management of Saltwater Intrusion in Groundwater. Optimization under Uncertainty

    OpenAIRE

    2004-01-01

    Coastal aquifers are very vulnerable to seawater intrusion through, for example, the overdraft of groundwater exploitation or insufficient recharge from upstream. Problems of salt-intrusion into groundwater have become a considerable concern in many countries with coastal areas. There have been a number of studies that have tried to simulate groundwater flow system in regions under threat of saltwater intrusion into coastal aquifers. These aquifer systems are characterized by either a single ...

  10. Shallow and Deep Networks Intrusion Detection System: A Taxonomy and Survey

    OpenAIRE

    Hodo, Elike; Bellekens, Xavier; Hamilton, Andrew; Tachtatzis, Christos; Atkinson, Robert,

    2017-01-01

    Intrusion detection has attracted a considerable interest from researchers and industries. The community, after many years of research, still faces the problem of building reliable and efficient IDS that are capable of handling large quantities of data, with changing patterns in real time situations. The work presented in this manuscript classifies intrusion detection systems (IDS). Moreover, a taxonomy and survey of shallow and deep networks intrusion detection systems is presented based on ...

  11. A Heuristic Clustering Algorithm for Intrusion Detection Based on Information Entropy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper studied on the clustering problem for intrusion detection with the theory of information entropy, it was put forward that the clustering problem for exact intrusion detection based on information entropy is NP-complete, therefore, the heuristic algorithm to solve the clustering problem for intrusion detection was designed, this algorithm has the characteristic of incremental development, it can deal with the database with large connection records from the internet.

  12. Network Intrusion Detection System – A Novel Approach

    Directory of Open Access Journals (Sweden)

    Krish Pillai

    2013-08-01

    Full Text Available Network intrusion starts off with a series of unsuccessful breakin attempts and results eventually with the permanent or transient failure of an authentication or authorization system. Due to the current complexity of authentication systems, clandestine attempts at intrusion generally take considerable time before the system gets compromised or damaging change is affected to the system giving administrators a window of opportunity to proactively detect and prevent intrusion. Therefore maintaining a high level of sensitivity to abnormal access patterns is a very effective way of preventing possible break-ins. Under normal circumstances, gross errors on the part of the user can cause authentication and authorization failures on all systems. A normal distribution of failed attempts should be tolerated while abnormal attempts should be recognized as such and flagged. But one cannot manage what one cannot measure. This paper proposes a method that can efficiently quantify the behaviour of users on a network so that transient changes in usage can be detected, categorized based on severity, and closely investigated for possible intrusion. The author proposes the identification of patterns in protocol usage within a network to categorize it for surveillance. Statistical anomaly detection, under which category this approach falls, generally uses simple statistical tests such as mean and standard deviation to detect behavioural changes. The author proposes a novel approach using spectral density as opposed to using time domain data, allowing a clear separation or access patterns based on periodicity. Once a spectral profile has been identified for network, deviations from this profile can be used as an indication of a destabilized or compromised network. Spectral analysis of access patterns is done using the Fast Fourier Transform (FFT, which can be computed in Θ(N log N operations. The paper justifies the use of this approach and presents preliminary

  13. INTRUSION DETECTION BASED ON THE SECOND-ORDER STOCHASTIC MODEL

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper presents a new method based on a second-order stochastic model for computer intrusion detection. The results show that the performance of the second-order stochastic model is better than that of a first-order stochastic model. In this study, different window sizes are also used to test the performance of the model. The detection results show that the second-order stochastic model is not so sensitive to the window size, comparing with the first-order stochastic model and other previous researches. The detection result of window sizes 6 and 10 is the same.

  14. Markov Graph Model Computation and Its Application to Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Markov model is usually selected as the base model of user action in the intrusion detection system (IDS). However, the performance of the IDS depends on the status space of Markov model and it will degrade as the space dimension grows. Here, Markov Graph Model (MGM) is proposed to handle this issue. Specification of the model is described, and several methods for probability computation with MGM are also presented. Based on MGM,algorithms for building user model and predicting user action are presented. And the performance of these algorithms such as computing complexity, prediction accuracy, and storage requirement of MGM are analyzed.

  15. MULTI SCALE TIME SERIES PREDICTION FOR INTRUSION DETECTION

    OpenAIRE

    G. Palanivel; K. Duraiswamy

    2014-01-01

    We propose an anomaly-based network intrusion detection system, which analyzes traffic features to detect anomalies. The proposed system can be used both in online as well as off-line mode for detecting deviations from the expected behavior. Although our approach uses network packet or flow data, it is general enough to be adaptable for use with any other network variable, which may be used as a signal for anomaly detection. It differs from most existing approaches in its use of wavelet trans...

  16. Mixing between a stratospheric intrusion and a biomass burning plume

    Directory of Open Access Journals (Sweden)

    J. Brioude

    2007-08-01

    Full Text Available Ozone, carbon monoxide, aerosol extinction coefficient, acetonitrile, nitric acid and relative humidity measured from the NOAA P3 aircraft during the TexAQS/GoMACCS 2006 experiment, indicate mixing between a biomass burning plume and a stratospheric intrusion in the free troposphere above eastern Texas. Lagrangian-based transport analysis and satellite imagery are used to investigate the transport mechanisms that bring together the tropopause fold and the biomass burning plume originating in southern California, which may affect the chemical budget of tropospheric trace gases.

  17. Mixing between a stratospheric intrusion and a biomass burning plume

    Directory of Open Access Journals (Sweden)

    J. Brioude

    2007-06-01

    Full Text Available Ozone, carbon monoxide, aerosol extinction coefficient, acetonitrile, nitric acid and relative humidity measured from the NOAA P3 aircraft during the TexAQS/GoMACCS 2006 experiment, indicate mixing between a biomass burning plume and a stratospheric intrusion in the free troposphere above eastern Texas. Lagrangian-based transport analysis and satellite imagery are used to investigate the transport mechanisms that bring together the tropopause fold and the biomass burning plume originating in southern California, which may affect the chemical budget of tropospheric trace gases.

  18. DUNDRUM Restriction-Intrusion of Liberty Ladders (DRILL) Audit Toolkit

    LENUS (Irish Health Repository)

    Kennedy, Harry G

    2011-09-01

    This series of rating \\'ladders\\' is intended to allow a quantitative and qualitative analysis of the use of restrictive and intrusive interventions as part of the therapeutic management of violence and aggression in psychiatric hospital settings. This is an evolving handbook. The ladders are currently organised to facilitate a behavioural analysis. Context, antecedents, behaviour, interventions, consequences are conceptualised as a series of events organised in temporal sequence so that causes, interactions and effects can be considered. The complexity of analysis possible is limited by the statistical power of the numbers of cases and events available. \\r\

  19. Performance Enhancement of Intrusion Detection using Neuro - Fuzzy Intelligent System

    Directory of Open Access Journals (Sweden)

    Dr. K. S. Anil Kumar

    2014-10-01

    Full Text Available This research work aims at developing hybrid algorithms using data mining techniques for the effective enhancement of anomaly intrusion detection performance. Many proposed algorithms have not addressed their reliability with varying amount of malicious activity or their adaptability for real time use. The study incorporates a theoretical basis for improvement in performance of IDS using K-medoids Algorithm, Fuzzy Set Algorithm, Fuzzy Rule System and Neural Network techniques. Also statistical significance of estimates has been looked into for finalizing the best one using DARPA network traffic datasets.

  20. Models of ash-laden intrusions in a stratified atmosphere

    Science.gov (United States)

    Hogg, Andrew; Johnson, Chris; Sparks, Steve; Huppert, Herbert; Woodhouse, Mark; Phillips, Jeremy

    2013-04-01

    Recent volcanic eruptions and the associated dispersion of ash through the atmosphere have led to widespread closures of airspace, for example the 2010 eruption of Eyjafjallajokull and 2011 eruption of Puyehue-Cordón Caulle. These episodes bring into sharp focus the need to predict quantitatively the transport and deposition of fine ash and in particular, its interaction with atmospheric wind. Many models of this process are based upon capturing the physics of advection with the wind, turbulence-induced diffusion and gravitational settling. Buoyancy-induced processes, associated with the density of the ash cloud and the background stratification of the atmosphere, are neglected and it is this issue that we address in this contribution. In particular, we suggest that the buoyancy-induced motion may account for the relatively thin distal ash layers that have been observed in the atmosphere and their relatively weak cross-wind spreading. We formulate a new model for buoyancy-driven spreading in the atmosphere in which we treat the evolving ash layer as relatively shallow so that its motion is predominantly horizontal and the pressure locally hydrostatic. The motion is driven by horizontal pressure gradients along with interfacial drag between the flowing ash layer and the surrounding atmosphere. Ash-laden fluid is delivered to this intrusion from a plume source and has risen through the atmosphere to its height of neutral buoyancy. The ash particles are then transported horizontally by the intrusion and progressively settle out of it to sediment through the atmosphere and form the deposit on the ground. This model is integrated numerically and analysed asymptotically in various regimes, including scenarios in which the atmosphere is quiescent and in which there is a sustained wind. The results yield predictions for the variation of the thickness of the intrusion with distance from the source and for how the concentration of ash is reduced due to settling. They