• A Mechanical Evaluation Of Alaskan White Spruce

      Syta, Dean Edward; Curtis, Kevin; Gasbarro, Tony; Raad, Luffi (1993)
      This project serves to demonstrate the usefulness of Alaskan White Spruce as a construction material. This is done through the development of allowable strength values for design purposes. Such values allow engineers to design structures using Alaskan White Spruce, increasing the usefulness of the wood species.<p> The mechanical properties of Alaskan White Spruce are investigated. Summaries of the mechanical properties and of subsequently developed allowable structural design values are given. Included are discussions of the Alaskan White Spruce species, general wood behavior, mechanical testing of wood, statistical data analysis, and allowable property development. Results are compared against the work of other researchers. Appendices of test data are given.<p> Test results and subsequent data analysis indicate Alaskan White Spruce possesses strength similar to Douglas-Fir/Larch lumber and higher strength than Spruce/Pine/Fir type lumbers. This indicates that Alaskan White Spruce may have considerable worth as a construction material. <p>
    • A Mechanism For Current Sheet Thinning In The Growth Phase Of Magnetospheric Substorms

      Hall, Fred, Iv; Otto, Antonius (2006)
      The thinning of the near-Earth current sheet during the growth phase of magnetospheric substorms is a fundamental problem of space physics. It is a characteristic of the slow, steady evolution of the magnetosphere during the growth phase, during which the bulk kinetic energy of the solar wind is transformed into and stored as magnetic field energy in the magnetotail lobes. The thin near-Earth current sheet at the end of the growth phase provides the conditions for the onset of the expansion phase, and is fundamentally important to understand the physical mechanism for the onset of the rapid evolution during which the stored energy is released. I propose that current sheet thinning occurs because of the evacuation of a 'magnetic flux reservoir' in the near-Earth magnetotail by convection to replace magnetic flux that is eroded on the dayside by magnetic reconnection. My hypothesis is able to predict basic properties of current sheet thinning, such as the location, temporal evolution, and dynamics of this process. I examined this new mechanism both conceptually and quantitatively. My conceptual considerations enabled the prediction of the location and duration of current sheet thinning. This location is largely independent of the detailed state of the magnetosphere. I examined this mechanism quantitatively through the use of a three-dimensional ideal MHD simulation. I was able to predict the duration of the growth phase by considering the time needed to deplete our proposed 'magnetic flux reservoir.' The simulation demonstrates the global increase of the current density in this reservoir, despite the removal of magnetic flux---which one would otherwise expect to lead to a decrease of current---as well as even greater local amplifications of the current density. The simulation results are even more significant because the model does not include other effects of the real magnetosphere that contribute to a further increase of the tail current. The increase in current density and thinning are found to be consistent with the amount of flux removed from the system. In addition, I have found a new explanation for the very thin bifurcated current sheets that have been reported in recent publications.
    • A Methodology For Intelligent Honeypot Deployment And Active Engagement Of Attackers

      Hecker, Christopher R.; Nance, Kara; Hay, Brian (2012)
      The internet has brought about tremendous changes in the way we see the world, allowing us to communicate at the speed of light, and dramatically changing the face of business forever. Organizations are able to share their business strategies and sensitive or proprietary information across the globe in order to create a sense of cohesiveness. This ability to share information across the vastness of the internet also allows attackers to exploit these different avenues to steal intellectual property or gather information vital to the national security of an entire nation. As technology advances to include more devices accessing an organization's network and as more business is handled via the internet, attackers' opportunities increase daily. Honeypots were created in response to this cyber warfare. Honeypots provide a technique to gather information about attackers performing reconnaissance on a network or device without the voluminous logs obtained by the majority of intrusion detection systems. This research effort provides a methodology to dynamically generate context-appropriate honeynets. Administrators are able to modify the system to conform to the target environment and gather the information passively or through increasing degrees of active scanning. The information obtained during the process of scanning the environment aids the administrator in creating a network topology and understanding the flux of devices in the network. This research continues the effort to defend an organization's networks against the onslaught of attackers.
    • A Multiple Stable Isotope Study Of Steller Sea Lions And Bowhead Whales: Signals Of A Changing Northern Environment

      Dehart, Pieter Andrew Philip; Wooller, Matthew J. (2006)
      The North Pacific and Arctic marine realm is currently experiencing dramatic environmental changes as a result of global climate change. Stable isotope analysis of western arctic bowhead whales (WABW, Balaena mysticetus ) and Steller sea lions (SSL, Eumetopias jubatus) were conducted to examine the influence of these changes on life history characteristics (migration and foraging) of these marine mammals. WABW baleen plates were analyzed for their stable oxygen and hydrogen isotope composition (delta 18O and deltaD) and were compared to the delta18O and deltaD in water and zooplankton prey along their seasonal migratory route. The delta18O and deltaD varied along the baleen (8 to 18�; -180 to -80�, respectively) and corresponded to stable isotopic differences in zooplankton from the winter (Bering Sea) and summer (eastern Beaufort Sea) habitats of WABW. Baleen delta18O and deltaD confirmed the seasonal annual migration of WABW and were subsequently compared to historical sea ice concentrations (SIC). This illustrated that WABW migration patterns appeared to have altered concomitant with changes in SIC. Years with a higher SIC (colder climate regimes) correlated with the largest difference in deltaD between winter and summer in WABW baleen during the period from 1972 to 1988. For a similar time period (1955 to 2000), the feeding ecology of SSL was also examined by analyzing the stable carbon and nitrogen isotope compositions (delta13C and delta 15N, respectively) of archived SSL bone and tooth collagen. Both delta 15N and delta13C varied greatly with location and sample year (14.6 to 20.5�; - 16.7 to -11.8�, respectively), with a significant change in delta13C observed around the 1976 regime shift. Bottom-up processes may have limited growth of SSL populations throughout this region over time, with animals focusing their foraging on offshore regions to mitigate this environmental change. Stable isotope analyses of historical samples of WABW (baleen) and SSL (bone and tooth collagen) both illustrated that recent environmental changes influenced the ecology (migration and feeding) of these marine mammals in the recent past.
    • A Narrative Study Of The Lived Experience Of Contemporary American Women In Intimate Relationships With Men Who Have Chronic Low Back Pain

      Heath, Gina; Brown, Jin (2008)
      Everyone experiences pain to one degree or another, but pain that has outlived its usefulness in assisting the body to avoid injury, and causes other physical and emotional complications, is known as chronic pain. In American medicine, chronic pain is described as that which persists longer than six months and is not relieved by standard medical care. Chronic pain usually leads to a spectrum of other physical and emotional complications, including sleep disturbance, loss of appetite, and severe depression, among many others. Creating and maintaining relationships with others takes effort and energy, and this is especially true in a marital relationship. Marriage between two able-bodied people is challenging enough, so the added variable of chronic pain forms new dimensions of relationship difficulty that must be addressed.
    • A nested watershed study in the Kuparuk River basin, arctic Alaska: Streamflow, scaling, and drainage basin structure

      Mcnamara, James Patrick (1997)
      The central hypothesis of this dissertation is that permafrost influences the form, function, and scaling of hydrologic and geomorphologic characteristics in the Kuparuk River basin in Northern Alaska. This problem was addressed using three approaches: field hydrologic studies, statistical scaling studies, and geomorphology studies using digital elevation models. Permafrost and snow exert significant controls on hydrologic processes in the Kuparuk River basin. Storm hydrographs show fast responses, long time lags, extended recessions, and high runoff/precipitation ratios. These features arise from the diminished storage capacity caused by permafrost. Summer storm flow compositions in the are dominated by old water, as is commonly observed in basins without permafrost. However, the thawing active layer imposes seasonal trends on storm flow composition and other streamflow characteristics. These seasonal trends are often masked by precipitation patterns. Significant differences exist in the spatial variability and scaling of streamflow between arctic and temperate basins. Streamflow in arctic basins is subject to simple scaling, whereas streamflow in temperate regions is subject to multiscaling. Since the variability of streamflow downstream results from the timing of storm hydrographs upstream, regional scaling differences may result from the differences in runoff generation mechanisms in basins with and without permafrost. Fractal analysis of channel networks, and the scaling of mass distribution suggest that channel networks in the Kuparuk River basin are underdeveloped. Hillslope water tracks convey water off slopes, but the organization of water tracks lacks universal characteristics of mass and energy distribution common to other rivers, and hence cannot be considered fluvial channels. However, the heads of water tracks are located where some theoretical models of channel initiation predict that channels should occur. A likely scenario is that a rudimentary channel network was formed soon after deglaciation, but was never allowed to develop into a mature network due to the limits that permafrost imposes on erosion. An encompassing conclusion is that the Kuparuk River basin is adjusted to arctic conditions in both form and function. Consequently, thermal changes to the existing permafrost condition may impose significant changes in the erosional development of channel networks and in the subsequent hydrologic response.
    • A Parent's Choice

      Hoffman, Jill; Marlow, Patrick (2010)
      In one rural Alaska school district, parents have a choice to place their child in an English only school or a Yup'ik immersion school. In the English only school, all subjects are taught in English. In the dual immersion school, English is introduced at third grade and progressively increases with each grade level until the sixth grade, when students exit the program. The researcher will seek to find why parents choose to place their child in the English only school or in the Yup'ik Immersion School. This inquiry is to help the researcher understand the thoughts and perceptions that are being held by parents and members in the community about each of the schools. The study will use qualitative research methodology that includes questionnaires and personal interviews to find out the thoughts and feelings that are being held by the parents. This research seeks to find the reasons why parents choose one school over the other. After reviewing the questionnaires, the researcher will select five parents from each school with various backgrounds to interview. The researcher will conduct ethnographic interviews designed to elicit more in-depth information. The interviews will be coded and emergent themes identified. Through data analysis, the researcher hopes to discover the reasons why parents are choosing each of the schools.
    • A Search For Thermospheric Composition Perturbations Due To Vertical Winds

      Krynicki, Matthew P.; Conde, Mark (2006)
      The thermosphere is generally in hydrostatic equilibrium, with winds blowing horizontally along stratified constant-pressure surfaces, driven by the dayside-to-nightside pressure gradient. A marked change in this paradigm resulted after Spencer et al. [1976] reported vertical wind measurements of 80 m&middot;s-1 from analyses of AE-C satellite data. It is now established that the thermosphere routinely supports large-magnitude (~30-150 m&middot;s-1) vertical winds at auroral latitudes. These vertical winds represent significant departure from hydrostatic and diffusive equilibrium, altering locally---and potentially globally---the thermosphere's and ionosphere's composition, chemistry, thermodynamics and energy budget. Because of their localized nature, large-magnitude vertical wind effects are not entirely known. This thesis presents ground-based Fabry-Perot Spectrometer OI(630.0)-nm observations of upper-thermospheric vertical winds obtained at Inuvik, NT, Canada and Poker Flat, AK. The wind measurements are compared with vertical displacement estimates at ~104 km2 horizontal spatial scales determined from a new modification to the electron transport code of Lummerzheim and Lilensten [1994] as applied to FUV-wavelength observations by POLAR spacecraft's Ultraviolet Imager [Torr et al. , 1995]. The modification, referred to as the column shift, simulates vertical wind effects such as neutral transport and disruption of diffusive equilibrium by vertically displacing the Hedin [1991] MSIS-90 [O2]/[N2] and [O]/([N2]+[O2]) mixing ratios and subsequently redistributing the O, O2, and N 2 densities used in the transport code. Column shift estimates are inferred from comparisons of UVI OI(135.6)-nm auroral observations to their corresponding modeled emission. The modeled OI(135.6)-nm brightness is determined from the modeled thermospheric response to electron precipitation and estimations of the energy flux and characteristic energy of the precipitation, which are inferred from UVI-observed Lyman-Birge-Hopfield N2 emissions in two wavelength ranges. Two-dimensional column shift maps identify the spatial morphology of thermospheric composition perturbations associated with auroral forms relative to the model thermosphere. Case-study examples and statistical analyses of the column shift data sets indicate that column shifts can be attributed to vertical winds. Unanticipated limitations associated with modeling of the OI(135.6)-nm auroral emission make absolute column shift estimates indeterminate. Insufficient knowledge of thermospheric air-parcel time histories hinders interpretations of point-to-point time series comparisons between column shifts and vertical winds.
    • A self-consistent time varying auroral model

      Min, Qilong; Rees, M. H.; Kan, J. R.; Lummerzheim, D.; Piacenza, R.; Stamnes, K. (1993)
      A time dependent model of auroral processes has been developed by self-consistently solving the electron transport equation, the ion continuity equations and the electron and ion energy equations. It is used to study the response of ionospheric and atmospheric properties in regions subjected to electron bombardment. The time history of precipitation events is computed for a variety of electron spectral energy distributions and flux magnitudes. Examples of daytime and night-time aurorae are presented. Precipitating energetic auroral electrons heat the ambient electrons and ions as well as enhancing the ionization rate which increases the ion concentration. The consequences of electric field acceleration and an inhomogeneous magnetic field in auroral electron transport in the topside ionosphere are investigated. Substantial perturbations of the low energy portion of the electron flux are produced: An upward directed electric field accelerates the downward directed flux of low energy secondary electrons and decelerates the upward directed component. Above about 400 km the inhomogeneous magnetic field produces anisotropies in the angular distribution of the electron flux. The effects of the perturbed energy distributions on auroral spectral emission features and on the electron temperature are noted. The response of the Hall and Pederson conductivities to auroral electron precipitation is discussed as a function of the characteristic energy of the spectral distribution.
    • A simulation study of magnetic reconnection processes at the dayside magnetopause

      Shi, Yong; Lee, L. C.; Swift, D. W.; Gosink, J.; Gatterdam, R.; Akasofu, S-I. (1989)
      In this thesis, the dayside reconnection processes are studied by using computer simulations. First, the global magnetic reconnection patterns at the dayside magnetopause are studied based on a two-dimensional incompressible magnetohydrodynamic (MHD) code. It is found that multiple X line reconnection may prevail at the dayside magnetopause when the magnetic Reynolds number is large ($>$200). The formation and subsequent poleward convection of magnetic islands are observed in the simulation. The Alfven Mach number of the solar wind, $M\sb{Asw}$, can also change the reconnection patterns. For a large $M\sb{Asw}$, reconnection tends to occur at the higher latitude region. Secondly, the structure of the dayside reconnection layer is studied by a two-dimensional compressible MHD simulation. In a highly asymmetric configuration typical of the dayside magnetopause, the pair of slow shocks bounding the reconnection layer in Petschek's symmetric model is found to be replaced by an intermediate shock on the magnetosheath side and a weak slow shock on the magnetospheric side. In addition, a mechanism for the enhancement of $B\sb y$, which is observed in the magnetopause current layer and magnetic flux tubes, is proposed.
    • A simulation study of three-dimensional magnetic reconnection

      Ma, Zhi-Wei; Lee, L. C.; Kan, J. R.; Shaw, G. E.; Smith, R. W.; Hawkins, J. G. (1994)
      The magnetic reconnection process plays an important role in the interaction between the solar wind and the magnetosphere. It leads to the transfer of energy from the solar wind into the magnetosphere. In this thesis, we study three-dimensional (3D) aspects of magnetic reconnection based on magnetohydrodynamic (MHD) simulations. First, we examine the magnetic field topology of magnetic flux ropes formed in multiple X line reconnection (MXR). It is found that the magnetic field topology depends on the relative extent and location of the two neighboring X lines. Magnetic flux ropes with either smooth or frayed ends are obtained in our simulations. For magnetic flux ropes with smooth ends, a major amount of magnetic flux is connected at each end to only one side of magnetopause. Second, the evolution of the core magnetic field in the magnetic flux tube is studied for various magnetic reconnection processes. We find that the 3D cases always lead to a larger enhancement of core field than the corresponding 2D cases since plasma can be squeezed out of the flux tube in the third direction. The MXR process gives rise to a larger increase of the core field than the single X line reconnection process. The core magnetic field can be enhanced to three times the ambient magnetic field strength in the 3D MXR process. Finally, we examine the generation and propagation of Alfven waves and field-aligned currents in the 3D reconnection process. For cases with a zero guide field, it is found that a large portion of the field-aligned currents ($\sim$40%) is located in the closed field line region. Both the pressure gradient term and inertia term contribute to the generation of field-aligned currents. For cases with nonzero guide field, one sense of field-aligned currents is dominant due to the presence of the initial field-aligned current. In these cases, the inertia term makes a major contribution to the redistribution of field-aligned currents. The influence of the initial guide field on the longitudinal shift of the current reversal site is found to be consistent with observations.
    • A Sounding Rocket Attitude Determination Algorithm Suitable For Implementation Using Low Cost Sensors

      Charlton, Mark Christopher; Hawkins, Joseph G. (2003)
      The development of low-cost sensors has generated a corresponding movement to integrate them into many different applications. One such application is determining the rotational attitude of an object. Since many of these low-cost sensors are less accurate than their more expensive counterparts, their noisy measurements must be filtered to obtain optimum results. This work describes the development, testing, and evaluation of four filtering algorithms for the nonlinear sounding rocket attitude determination problem. Sun sensor, magnetometer, and rate sensor measurements are simulated. A quatenion formulation is used to avoid singularity problems associated with Euler angles and other three-parameter approaches. Prior to filtering, Gauss-Newton error minimization is used to reduce the six reference vector components to four quaternion components that minimize a quadratic error function. Two of the algorithms are based on the traditional extended Kalman filter (EKF) and two are based on the recently developed unscented Kalman filter (UKF). One of each incorporates rate measurements, while the others rely on differencing quaternions. All incorporate a simplified process model for state propagation allowing the algorithms to be applied to rockets with different physical characteristics, or even to other platforms. Simulated data are used to develop and test the algorithms, and each successfully estimates the attitude motion of the rocket, to varying degrees of accuracy. The UKF-based filter that incorporates rate sensor measurements demonstrates a clear performance advantage over both EKFs and the UKF without rate measurements. This is due to its superior mean and covariance propagation characteristics and the fact that differencing generates noisier rates than measuring. For one sample case, the "pointing accuracy" of the rocket spin axis is improved by approximately 39 percent over the EKF that uses rate measurements and by 40 percent over the UKF without rates. The performance of this UKF-based algorithm is evaluated under other-than-nominal conditions and proves robust with respect to data dropouts, motion other than predicted and over a wide range of sensor accuracies. This UKF-based algorithm provides a viable low cost alternative to the expensive attitude determination systems currently employed on sounding rockets.
    • A statewide training model for supported employment using master trainers

      Wilcox, David Allen; Mohatt, Gerald; Risley, Todd R.; Dinges, Norman; Dowrick, Peter W.; Kleinke, Chris; Owens, Jesse; Ryan-Vincek, Susan; Ward, Karen M. (1996)
      Alaska's vast land mass and diversified urban, rural, and remote communities require innovative training curricula to meet training needs in supported employment. A competency-based training program using an independent learning format and master trainers was developed to meet these extreme needs. These training methods were evaluated with survey instruments at the time of training and at 3 months, 6 months, and 1 year follow up. The data demonstrate that the training materials as well as the independent study format and master trainer model were effective training methods. We conclude that the training methods developed are effective in meeting the diverse training needs of urban, rural, and remote sites.
    • A study of one-dimensional nonlinear hydromagnetic waves and collisionless shocks

      Lyu, Ling-Hsiao; Kan, J. R.; Akasofu, S.-I.; Biswas, N. N.; Olson, J. V.; Swift, D. W. (1991)
      A variety of nonlinear hydromagnetic waves have been observed in the collisionless solar wind plasma. A comprehensive theoretical study of nonlinear hydromagnetic waves, including rotational discontinuities and collisionless shocks, is carried out in this thesis by means of both analytical solutions and numerical simulations. Nonlinear hydromagnetic waves are governed by the interplay of the dispersion process, the collisionless dissipation process and the nonlinear steepening process. The purpose of this thesis is to understand the nonlinear behavior of hydromagnetic waves in terms of these fundamental processes. It is shown that the rotational discontinuity structures observed in the solar wind and at the magnetopause are nonlinear Alfven wave solutions of the collisionless two-fluid plasma equations. In these nonlinear wave solutions, nonlinear steepening is self-consistently balanced by dispersion. Collisionless viscous dissipation is the dominant dissipation in high Mach number shocks, which converts the flow energy into thermal energy. Hybrid simulations show that the collisionless viscous dissipation can result from the reflection and pitch-angle scattering of incoming ions flowing through the magnetic structures in the shock transition region. Collisionless dissipations in hydromagnetic shocks is governed by the magnetic structures in the shock transition region. The dissipation in turn can modify the wave structures and balance the nonlinear steepening. However, such delicate balance of the dispersion, dissipation, and nonlinear steepening has been observed to break down momentarily in high Mach number quasi-parallel shocks. This leads to the so-called cyclic shock front reformation seen in the hybrid simulations. The shock front reformation can be explained in terms of momentary off-balance between the dispersion-dissipation on the one hand and the nonlinear steepening on the other hand. The off-balance occurs after a significant fraction of incoming ions are reflected. Each off-balance lasts a few ion gyro periods, which governs the shock front reformation time scale.
    • A study of the link between cloud microphysics and climate change

      Hu, Yong-Xiang; Stamnes, Knut; Musgrave, David; Rees, Manfred; Shaw, Glenn E.; Tsay, Shee-Chee; Watkins, Brenton (1994)
      The climate related cloud radiative properties (fluxes and heating rates) are found to be determined by the second and the third moments of the cloud droplet size distribution. The detailed distribution of the cloud droplet size is unnecessary to obtain for climate purposes. An accurate parameterization of cloud optical properties suitable for climate models is developed. A new radiative-convective model has been developed and used for studying cloud-climate interactions. The energy balance at the Earth-atmosphere interface is treated in a self-consistent manner which avoids artificial tuning. The cloud radiative properties are accurately incorporated and are suitable for sensitivity studies of cloud-radiation-climate interactions. A sensitivity study of role of the cloud microphysical properties in the climate system is performed by studying the impact of cloud radiative forcing on the equilibrium state temperature. The cloud equivalent radius is found to be a very important variable in the climate system. A climate sensitivity study is performed to highlight the important role of the cloud absorption. An adjoint radiative transfer method is developed for use in the cloudy and aerosol-loaded atmospheres. The physical meaning of the adjoint radiative properties are discussed. The method is expected to be useful in climate modeling and remote sensing studies. A preliminary study of the atmospheric irreversibility is performed to elucidate the connection between cloud microphysical properties and the macrophysical direction of global climate. A variational principle which describes the macrophysical character of the climate system is established.