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Detecting insider activity using enhanced directory virtualization

Claycomb, William R.

Insider threats often target authentication and access control systems, which are frequently based on directory services. Detecting these threats is challenging, because malicious users with the technical ability to modify these structures often have sufficient knowledge and expertise to conceal unauthorized activity. The use of directory virtualization to monitor various systems across an enterprise can be a valuable tool for detecting insider activity. The addition of a policy engine to directory virtualization services enhances monitoring capabilities by allowing greater flexibility in analyzing changes for malicious intent. The resulting architecture is a system-based approach, where the relationships and dependencies between data sources and directory services are used to detect an insider threat, rather than simply relying on point solutions. This paper presents such an architecture in detail, including a description of implementation results.

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TYPE Conference YEAR 2010
OSTI

Expected result of firing an ICE load on Z without vacuum

Struve, Kenneth; Lemke, Raymond W.; Savage, Mark E.

In addressing the issue of the determining the hazard categorization of the Z Accelerator of doing Special Nuclear Material (SNM) experiments the question arose as to whether the machine could be fired with its central vacuum chamber open, thus providing a path for airborne release of SNM materials. In this report we summarize calculations that show that we could only expect a maximum current of 460 kA into such a load in a long-pulse mode, which will be used for the SNM experiments, and 750 kA in a short-pulse mode, which is not useful for these experiments. We also investigated the effect of the current for both cases and found that for neither case is the current high enough to either melt or vaporize these loads, with a melt threshold of 1.6 MA. Therefore, a necessary condition to melt, vaporize, or otherwise disperse SNM material is that a vacuum must exist in the Z vacuum chamber. Thus the vacuum chamber serves as a passive feature that prevents any airborne release during the shot, regardless of whatever containment may be in place.

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TYPE SAND Report YEAR 2010
DOIOSTI

Compressively sensed complex networks

Pinar, Ali P.; Dunlavy, Daniel M.

The aim of this project is to develop low dimension parametric (deterministic) models of complex networks, to use compressive sensing (CS) and multiscale analysis to do so and to exploit the structure of complex networks (some are self-similar under coarsening). CS provides a new way of sampling and reconstructing networks. The approach is based on multiresolution decomposition of the adjacency matrix and its efficient sampling. It requires preprocessing of the adjacency matrix to make it 'blocky' which is the biggest (combinatorial) algorithm challenge. Current CS reconstruction algorithm makes no use of the structure of a graph, its very general (and so not very efficient/customized). Other model-based CS techniques exist, but not yet adapted to networks. Obvious starting point for future work is to increase the efficiency of reconstruction.

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TYPE Conference YEAR 2010
OSTI

Transient PVT measurements and model predictions for vessel heat transfer. Part II

Winters, William S.; Evans, Gregory H.; Rice, Steven F.; Paradiso, Nicholas J.; Felver, Todd G.

Part I of this report focused on the acquisition and presentation of transient PVT data sets that can be used to validate gas transfer models. Here in Part II we focus primarily on describing models and validating these models using the data sets. Our models are intended to describe the high speed transport of compressible gases in arbitrary arrangements of vessels, tubing, valving and flow branches. Our models fall into three categories: (1) network flow models in which flow paths are modeled as one-dimensional flow and vessels are modeled as single control volumes, (2) CFD (Computational Fluid Dynamics) models in which flow in and between vessels is modeled in three dimensions and (3) coupled network/CFD models in which vessels are modeled using CFD and flows between vessels are modeled using a network flow code. In our work we utilized NETFLOW as our network flow code and FUEGO for our CFD code. Since network flow models lack three-dimensional resolution, correlations for heat transfer and tube frictional pressure drop are required to resolve important physics not being captured by the model. Here we describe how vessel heat transfer correlations were improved using the data and present direct model-data comparisons for all tests documented in Part I. Our results show that our network flow models have been substantially improved. The CFD modeling presented here describes the complex nature of vessel heat transfer and for the first time demonstrates that flow and heat transfer in vessels can be modeled directly without the need for correlations.

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TYPE SAND Report YEAR 2010
DOIOSTI

Initial inclusion of thermodynamic considerations in Kayenta

Strack, Otto E.; Bishop, Joseph E.

A persistent challenge in simulating damage of natural geological materials, as well as rock-like engineered materials, is the development of efficient and accurate constitutive models. The common feature for these brittle and quasi-brittle materials are the presence of flaws such as porosity and network of microcracks. The desired models need to be able to predict the material responses over a wide range of porosities and strain rate. Kayenta (formerly called the Sandia GeoModel) is a unified general-purpose constitutive model that strikes a balance between first-principles micromechanics and phenomenological or semi-empirical modeling strategies. However, despite its sophistication and ability to reduce to several classical plasticity theories, Kayenta is incapable of modeling deformation of ductile materials in which deformation is dominated by dislocation generation and movement which can lead to significant heating. This stems from Kayenta's roots as a geological model, where heating due to inelastic deformation is often neglected or presumed to be incorporated implicitly through the elastic moduli. The sophistication of Kayenta and its large set of extensive features, however, make Kayenta an attractive candidate model to which thermal effects can be added. This report outlines the initial work in doing just that, extending the capabilities of Kayenta to include deformation of ductile materials, for which thermal effects cannot be neglected. Thermal effects are included based on an assumption of adiabatic loading by computing the bulk and thermal responses of the material with the Kerley Mie-Grueneisen equation of state and adjusting the yield surface according to the updated thermal state. This new version of Kayenta, referred to as Thermo-Kayenta throughout this report, is capable of reducing to classical Johnson-Cook plasticity in special case single element simulations and has been used to obtain reasonable results in more complicated Taylor impact simulations in LS-Dyna. Despite these successes, however, Thermo-Kayenta requires additional refinement for it to be consistent in the thermodynamic sense and for it to be considered superior to other, more mature thermoplastic models. The initial thermal development, results, and required refinements are all detailed in the following report.

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TYPE SAND Report YEAR 2010
DOIOSTI

Computational mechanics for geosystems management to support the energy and natural resources mission

Stone, Charles M.

U.S. energy needs - minimizing climate change, mining and extraction technologies, safe waste disposal - require the ability to simulate, model, and predict the behavior of subsurface systems. They propose development of a coupled thermal, hydrological, mechanical, chemistry (THMC) modeling capability for massively parallel applications that can address these critical needs. The goal and expected outcome of this research is a state-of-the-art, extensible, simulation capability, based upon SIERRA Mechanics, to address multiphase, multicomponent reactive transport coupled to nonlinear geomechanics in heterogeneous (geologic) porous materials. The THMC code provides a platform for integrating research in numerical mathematics and algorithms for chemically reactive multiphase systems with computer science research in adaptive coupled solution control and framework architecture.

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TYPE Conference YEAR 2010
OSTI

Scene kinetics mitigation using factor analysis with derivative factors

Scholand, Andrew J.; Larson, Kurt; Melgaard, David K.

Line of sight jitter in staring sensor data combined with scene information can obscure critical information for change analysis or target detection. Consequently before the data analysis, the jitter effects must be significantly reduced. Conventional principal component analysis (PCA) has been used to obtain basis vectors for background estimation; however PCA requires image frames that contain the jitter variation that is to be modeled. Since jitter is usually chaotic and asymmetric, a data set containing all the variation without the changes to be detected is typically not available. An alternative approach, Scene Kinetics Mitigation, first obtains an image of the scene. Then it computes derivatives of that image in the horizontal and vertical directions. The basis set for estimation of the background and the jitter consists of the image and its derivative factors. This approach has several advantages including: (1) only a small number of images are required to develop the model, (2) the model can estimate backgrounds with jitter different from the input training images, (3) the method is particularly effective for sub-pixel jitter, and (4) the model can be developed from images before the change detection process. In addition the scores from projecting the factors on the background provide estimates of the jitter magnitude and direction for registration of the images. In this paper we will present a discussion of the theoretical basis for this technique, provide examples of its application, and discuss its limitations.

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TYPE Conference YEAR 2010
OSTI

Technical Area V (TA-V) transformation project close-out report

Wheeler, David

Sandia National Laboratories (SNL) Technical Area V (TA-V) has provided unique nuclear experimental environments for decades. The technologies tested in TA-V facilities have furthered the United States Nuclear Weapons program and has contributed to the national energy and homeland security mission. The importance of TA-V working efficiently to produce an attractive and effective platform for experiments should not be underestimated. Throughout its brief history, TA-V has evolved to address multiple and diverse sets of requirements. These requirements evolved over many years; however, the requirements had not been managed nor communicated comprehensively or effectively. A series of programmatic findings over several years of external audits was evidence of this downfall. Today, these same requirements flow down through a new TA-V management system that produces consistently applied and reproducible approaches to work practices. In 2008, the TA-V department managers assessed the state of TA-V services and work activities to understand how to improve customer interfaces, stakeholders perceptions, and workforce efficiencies. The TA-V management team initiated the TA-V Transformation Project after they deemed the pre-June 2008 operational model to be ineffective in managing work and in providing integrated, continuous improvement to TA-V processes. This report summarizes the TA-V Transformation Project goals, activities, and accomplishments.

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TYPE SAND Report YEAR 2010
DOIOSTI

Eigenvalue analysis of uncertain ODE systems

Debusschere, Bert; Berry, Robert D.; Najm, Habib N.

The Polynomial chaos expansion provides a means of representing any L2 random variable as a sum of polynomials that are orthogonal with respect to a chosen measure. Examples include the Hermite polynomials with Gaussian measure on the real line and the Legendre polynomials with uniform measure on an interval. Polynomial chaos can be used to reformulate an uncertain ODE system, using Galerkin projection, as a new, higher-dimensional, deterministic ODE system which describes the evolution of each mode of the polynomial chaos expansion. It is of interest to explore the eigenstructure of the original and reformulated ODE systems by studying the eigenvalues and eigenvectors of their Jacobians. In this talk, we study the distribution of the eigenvalues of the two Jacobians. We outline in general the location of the eigenvalues of the new system with respect to those of the original system, and examine the effect of expansion order on this distribution.

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TYPE Conference YEAR 2010
OSTI

Towards a mutually reinforcing future : opportunities to integrate nuclear weapons stewardship and arms control objectives

Sanders, Lani M.; Deland, Sharon M.; Pregenzer, Arian L.

2010 NPR and President Obama's 2009 Prague Speech highlighted two key objectives with an inherent underlying tension: (1) Moving towards a world free of nuclear weapons; and (2) Sustaining a safe, secure, and effective nuclear arsenal. Objective 1 depends, inter alia, upon reductions in stockpiles at home and abroad and maintaining stability. Objective 2 depends upon needed investments in modernization and life extension. Objectives being pursued predominantly in parallel by largely separate communities.

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TYPE Conference YEAR 2010
OSTI

Towards secure virtual directories : a risk analysis framework

Claycomb, William R.

Directory services are used by almost every enterprise computing environment to provide data concerning users, computers, contacts, and other objects. Virtual directories are components that provide directory services in a highly customized manner. Unfortunately, though the use of virtual directory services are widespread, an analysis of risks posed by their unique position and architecture has not been completed. We present a detailed analysis of six attacks to virtual directory services, including steps for detection and prevention. We also describe various categories of attack risks, and discuss what is necessary to launch an attack on virtual directories. Finally, we present a framework to use in analyzing risks to individual enterprise computing virtual directory instances. We show how to apply this framework to an example implementation, and discuss the benefits of doing so.

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TYPE Conference YEAR 2010
OSTI

Beyond game effectiveness. Part II, a qualitative study of multi-role experiential learning

Fabian, Nathan; Tucker, Eilish M.

The present paper is the second in a series published at I/ITSEC that seeks to explain the efficacy of multi-role experiential learning employed to create engaging game-based training methods transitioned to the U.S. Army, U.S. Army Special Forces, Civil Affairs, and Psychological Operations teams. The first publication (I/ITSEC 2009) summarized findings from a quantitative study that investigated experiential learning in the multi-player, PC-based game module transitioned to PEO-STRI, DARWARS Ambush! NK (non-kinetic). The 2009 publication reported that participants of multi-role (Player and Reflective Observer/Evaluator) game-based training reported statistically significant learning and engagement. Additionally when the means of the two groups (Player and Reflective Observer/Evaluator) were compared, they were not statistically significantly different from each other. That is to say that both playing as well as observing/evaluating were engaging learning modalities. The Observer/Evaluator role was designed to provide an opportunity for real-time reflection and meta-cognitive learning during game play. Results indicated that this role was an engaging way to learn about communication, that participants learned something about cultural awareness, and that the skills they learned were helpful in problem solving and decision-making.

The present paper seeks to continue to understand what and how users of non-kinetic game-based missions learn by revisiting the 2009 quantitative study with further investigation such as stochastic player performance analysis using latent semantic analyses and graph visualizations. The results are applicable to First-Person game-based learning systems designed to enhance trainee intercultural communication, interpersonal skills, and adaptive thinking. In the full paper, we discuss results obtained from data collected from 78 research participants of diverse backgrounds who trained by engaging in tasks directly, as well as observing and evaluating peer performance in real-time. The goal is two-fold. One is to quantify and visualize detailed player performance data coming from game play transcription to give further understanding to the results in the 2009 I/ITSEC paper. The second is to develop a set of technologies from this quantification and visualization approach into a generalized application tool to be used to aid in future games’ development of player/learner models and game adaptation algorithms.

Specifically, this paper addresses questions such as, “Are there significant differences in one's experience when an experiential learning task is observed first, and then performed by the same individual?” “Are there significant differences among groups participating in different roles in non-kinetic engagement training, especially when one role requires more active participation that the other?” “What is the impact of behavior modeling on learning in games?” In answering these questions the present paper reinforces the 2009 empirical study conclusion that contrary to current trends in military game development, experiential learning is enhanced by innovative training approaches designed to facilitate trainee mastery of reflective observation and abstract conceptualization as much as performance-based skills.

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TYPE Conference YEAR 2010
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Effect of CO2 gasification reaction on oxycombustion of pulverized coal char

Shaddix, Christopher R.

For oxy-combustion with flue gas recirculation, as is commonly employed, it is recognized that elevated CO{sub 2} levels affect radiant transport, the heat capacity of the gas, and other gas transport properties. A topic of widespread speculation has concerned the effect of the CO{sub 2} gasification reaction with coal char on the char burning rate. To give clarity to the likely impact of this reaction on the oxy-fuel combustion of pulverized coal char, the Surface Kinetics in Porous Particles (SKIPPY) code was employed for a range of potential CO{sub 2} reaction rates for a high-volatile bituminous coal char particle (130 {micro}m diameter) reacting in several O{sub 2} concentration environments. The effects of boundary layer chemistry are also examined in this analysis. Under oxygen-enriched conditions, boundary layer reactions (converting CO to CO{sub 2}, with concomitant heat release) are shown to increase the char particle temperature and burning rate, while decreasing the O{sub 2} concentration at the particle surface. The CO{sub 2} gasification reaction acts to reduce the char particle temperature (because of the reaction endothermicity) and thereby reduces the rate of char oxidation. Interestingly, the presence of the CO{sub 2} gasification reaction increases the char conversion rate for combustion at low O{sub 2} concentrations, but decreases char conversion for combustion at high O{sub 2} concentrations. These calculations give new insight into the complexity of the effects from the CO{sub 2} gasification reaction and should help improve the understanding of experimentally measured oxy-fuel char combustion and burnout trends in the literature.

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TYPE Conference YEAR 2010
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Self-assembly of photo-reduced graphene-titania films

Washburn, Cody; Bell, Nelson S.; Mckenzie, Bonnie; Brumbach, Michael T.

In an aim to develop photo-responsive composites, the UV photo-reduction of aqueous titanium oxide nanoparticle-graphene oxide (TiO{sub 2}-GO) dispersions (Lambert et al. J Phys. Chem. 2010 113 (46), 19812-19823) was undertaken. Photo-reduction led to the formation of a black precipitate as well as a soluble portion, comprised of titanium oxide nanoparticle-reduced graphene oxide (TiO{sub 2}-RGO). When allowed to slowly evaporate, self assembled titanium oxide nanoparticle-graphene oxide (SA-TiO{sub 2}-RGO) films formed at the air-liquid interface of the solution. The thickness of SARGO-TiO{sub 2} films range from {approx}30-100 nm when deposited on substrates, and appear to be comprised of a mosaic assembly of graphene nanosheets and TiO{sub 2}, as observed by scanning electron microscopy. Raman spectroscopy and X-ray photoelectron spectroscopy indicate that the graphene oxide is only partially reduced in the SA-TiO{sub 2}-RGO material. These films were also deposited onto inter-digitated electrodes and their photo-responsive behavior was examined. UV-exposure lead to a {approx} 200 kOhm decrease in resistance across the device, resulting in a cathodically biased film. The cathodic bias of the films was utilized for the subsequent reduction of Ag(NO{sub 3}) into silver (Ag) nanoparticles, forming a ternary Ag-(SA-RGO-TiO{sub 2}) composite. Various aspects of the self assembled films, their photoconductive properties as well as potential applications will be presented.

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TYPE Conference YEAR 2010
OSTI

Selected test results from the neosonic polymer Li-ion battery

Hund, Thomas D.; Ingersoll, David

The performance of the Neosonic polymer Li-ion battery was measured using a number of tests including capacity, capacity as a function of temperature, ohmic resistance, spectral impedance, hybrid pulsed power test, utility partial state of charge (PSOC) pulsed cycle test, and an over-charge/voltage abuse test. The goal of this work was to evaluate the performance of the polymer Li-ion battery technology for utility applications requiring frequent charges and discharges, such as voltage support, frequency regulation, wind farm energy smoothing, and solar photovoltaic energy smoothing. Test results have indicated that the Neosonic polymer Li-ion battery technology can provide power levels up to the 10C{sub 1} discharge rate with minimal energy loss compared to the 1 h (1C) discharge rate. Two of the three cells used in the utility PSOC pulsed cycle test completed about 12,000 cycles with only a gradual loss in capacity of 10 and 13%. The third cell experienced a 40% loss in capacity at about 11,000 cycles. The DC ohmic resistance and AC spectral impedance measurements also indicate that there were increases in impedance after cycling, especially for the third cell. Cell No.3 impedance Rs increased significantly along with extensive ballooning of the foil pouch. Finally, at a 1C (10 A) charge rate, the over charge/voltage abuse test with cell confinement similar to a multi cell string resulted in the cell venting hot gases at about 45 C 45 minutes into the test. At 104 minutes into the test the cell voltage spiked to the 12 volt limit and continued out to the end of the test at 151 minutes. In summary, the Neosonic cells performed as expected with good cycle-life and safety.

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TYPE SAND Report YEAR 2010
DOIOSTI

The Nuclear Posture Review (NPR) : are we safer?

Brune, Nancy E.

Nuclear Posture Review (NPR) is designed to make world safer by reducing the role of U.S. nuclear weapons and reducing the salience of nuclear weapons. U.S. also seeks to maintain a credible nuclear deterrent and reinforce regional security architectures with missile defenses and other conventional military capabilities. But recent studies suggest that nuclear proliferation is a direct response to the perceived threat of U.S. conventional capabilities not U.S. nuclear stockpile. If this is true, then the intent of the NPR to reduce the role and numbers of nuclear weapons and strengthen conventional military capabilities may actually make the world less safe. First stated objective of NPR is to reduce the role and numbers of U.S. nuclear weapons, reduce the salience of nuclear weapons and move step by step toward eliminating them. Second stated objective is a reaffirmation of U.S. commitment to maintaining a strong deterrent which forms the basis of U.S. assurances to allies and partners. The pathway - made explicit throughout the NPR - for reducing the role and numbers of nuclear weapons while maintaining a credible nuclear deterrent and reinforcing regional security architectures is to give conventional forces and capabilities and missile defenses (e.g. non-nuclear elements) a greater share of the deterrence burden.

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TYPE Conference YEAR 2010
OSTI

Magnetoencephalography with a two-color pump probe atomic magnetometer

Johnson, Cort N.; Schwindt, Peter D.

The authors have detected magnetic fields from the human brain with a compact, fiber-coupled rubidium spin-exchange-relaxation-free magnetometer. Optical pumping is performed on the D1 transition and Faraday rotation is measured on the D2 transition. The beams share an optical axis, with dichroic optics preparing beam polarizations appropriately. A sensitivity of <5 fT/{radical}Hz is achieved. Evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer. Recordings were validated by comparison with those taken by a commercial magnetoencephalography system. The design is amenable to arraying sensors around the head, providing a framework for noncryogenic, whole-head magnetoencephalography.

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TYPE Conference YEAR 2010
OSTI
Results 72501–72600 of 99,299
Results 72501–72600 of 99,299