Approved for public release; distribution is unlimited / In the boost phase interception of ballistic missiles, determining the exact position of a ballistic missile has a significant importance. Several sensors are used to detect and track the missile. These sensors differ from each other in many different aspects. The outputs of radars give range, elevation and azimuth information of the target while space based infrared sensors give elevation and azimuth information. These outputs have to be combined (fused) achieve better position information for the missile. The architecture that is used in this thesis is decision level fusion architecture. This thesis examines four algorithms to fuse the results of radar sensors and space based infrared sensors. An averaging technique, a weighted averaging technique, a Kalman filtering approach and a Bayesian technique are compared. The ballistic missile boost phase segment and the sensors are modeled in MATLAB. The missile vector and dynamics are based upon Newton's laws and the simulation uses an earth-centered coordinate system. The Bayesian algorithm has the best performance resulting in a rms missile position error of less than 20 m. / 1st Lieutenant, Turkish Air Force

As the United States Navy strives to attain a myriad of situational awareness systems that provide the functionality and interoperability required for future missions, the fundamental idea of open architecture is beginning to promulgate throughout the Department. In order to make rational, informed decisions concerning the processes and systems that will be integrated to provide this situational awareness, an analytical method must be used to identify process deficiencies and produce quantifiable measurement indicators. This thesis will apply the Knowledge Value Added methodology to the current processes involved in track management aboard the AEGIS and Ship Self Defense System (SSDS) platforms. Additional analysis will be conducted based on notional changes that could occur were the systems designed using an open architecture approach. A valuation based on knowledge assets will be presented in order to.

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Adolescent Idiopathic Scoliosis (AIS) is typically treated surgically by Posterior Spinal Fusion (PSF) surgery. Intravenous analgesics and oral opioids are commonly used for pain management. Several adjunct therapies are used in addition to the standard treatments. One of these therapies is the use of dexmedetomidine (dex). Though dex has been found to be an effective sedative for post‐operative patients, there are also several adverse effects that are associated with its use. The purpose of this study was to investigate the effectiveness and overall benefit of using dex for pain control for patients undergoing PSF for AIS. IRB approval was obtained. A group of 43 patients with AIS undergoing PSF and using Dex for adjunctive pain control were matched with 43 patients who did not use Dex. The groups were matched based on gender, age, height, weight, and level of spinal fusion. During the patients’ post‐operative hospital stay, the total opioid use and clinical pain scores were compared between the two groups using t‐tests, with significance set at p<0.05. Total opiate use was 239.6 morphine equivalent doses in the non‐Dex (control) group and 246.2 in the group that received Dex (p=0.72). The average pain score in the control group was 2.3, and the group that received Dex was 2.6 (p =0.43). There were no differences in the complication rate between the two groups, specifically the oversedation rates and pulmonary complications. Lastly, the average length of stay for the control group was 4.8 days compared to the dex group, which was 5.0 days (p=0.35). Although adjunctive pain modalities may be very useful in the treatment of postoperative pain after PSF in patients with AIS, the use of Dex in this cohort did not improve pain scores, lower opioid use, or lower the LOS. Based on these results, we do not recommend the routine use of dexmedetomidine as an adjunctive pain control modality. Adjunctive modalities are important in pain control in patients with AIS undergoing PSF, but the use of dexmedotomidine was not effective in improving pain control.

A Thesis submitted to The University of Arizona College of Medicine - Phoenix in partial fulfillment of the requirements for the Degree of Doctor of Medicine. / Surgical correction of Adolescent Idiopathic Scoliosis (AIS) carries a substantial risk of complication. The literature supports improved perioperative outcomes through the two surgeon strategy in other complex orthopedic procedures. Does the presence of 2 versus 1 attending surgeons affect the perioperative morbidity of posterior spinal fusion (PSF) in patients with AIS curves greater than 70°? We reviewed the database from a large regional children’s hospital of all patients with AIS curves greater than 70° who underwent PSF from 2009‐2014 and divided the cohort into single versus 2‐surgeon groups (28 vs. 19 cases, respectively). We analyzed cases for length of surgery, estimated blood loss, and length of stay. The groups were identical when comparing age, gender, spinal levels fused, and average ASA score. However, the average Cobb angle in the single surgeon group was significantly less than in the 2 surgeon group at 78.4 vs 84.0 degrees, respectively (p=0.049). Mean operative time for single versus 2 surgeons was 238 (SD 48) vs 212 (SD 46) minutes (p=0.078). Mean percent estimated blood loss was 26% (SD 14.1) for single surgeon vs 31% (SD 14.9) for 2 surgeons (p=0.236), and mean estimated blood loss for single surgeon vs 2 surgeons was 830ml (SD 361) vs 1045ml (SD 346) (p=0.052). Mean length of stay was significantly decreased in the 2 surgeon group at 5.16 days (SD 1.7) versus the single surgeon group at 6.82 days (SD 6.82) (p=0.002). The use of 2 surgeons in AIS deformity correction at an experienced regional children’s hospital did not improve clinical outcomes. The average length of stay was reduced in the two‐surgeon group, but there was no significant impact on blood loss or operative time. However, this study does not rule out the potential for positive impact with a two‐surgeon strategy, and given previous supportive data in the literature, this approach should further evaluated to determine its effect on improving perioperative outcomes.

Plasma-wall interaction plays an essential role in the performance and safety of a fusion reactor. This thesis focuses on the impact of material migration on plasma-facing components. It is based on experiments performed in tokamaks: JET, TEXTOR and ASDEX Upgrade. The objectives of the experiments were to assess fuel and impurity removal under ion cyclotron wall conditioning (ICWC) and plasma impact on diagnostic mirrors. In wall conditioning studies, tracer techniques based on the injection of rare isotopes (15N, 18O) were used to determine conclusively the impact of the respective gases. For the first time, probe surfaces and wall components exposed to ICWC were examined by surface analysis methods. Discharges in hydrogen were the most efficient to erode carbon co-deposits, resulting in a reduction of the initial deuterium content by a factor of two. It was also found that impurities desorbed under ICWC are partly re-deposited on the wall. Plasma impact on diagnostic mirrors was determined by surface analysis of test mirrors exposed at JET. Reflectivity of mirrors from the divertor region was severely decreased due to deposits of beryllium, deuterium, carbon and other impurities. This result points out the need to develop mirror maintenance procedures. Neutron damage on mirrors was simulated by ion irradiation in an ion implanter. It was shown that damage levels similar to those expected in the first wall of a fusion reactor do not produce a significant change in reflectivity. / <p>QC 20160819</p>

The transport of heat that results from turbulence is a major factor limiting the temperature gradient, and thus the performance, of fusion devices. We use nonlinear simulations to show that a toroidal equilibrium scale sheared flow can completely suppress the turbulence across a wide range of flow gradient and temperature gradient values. We demonstrate the existence of a bifurcation across this range whereby the plasma may transition from a low flow gradient and temperature gradient state to a higher flow gradient and temperature gradient state. We show further that the maximum temperature gradient that can be reached by such a transition is limited by the existence, at high flow gradient, of subcritical turbulence driven by the parallel velocity gradient (PVG). We use linear simulations and analytic calculations to examine the properties of the transiently growing modes which give rise to this subcritical turbulence, and conclude that there may be a critical value of the ratio of the PVG to the suppressing perpendicular gradient of the velocity (in a tokamak this ratio is equal to q/ε where q is the magnetic safety factor and ε the inverse aspect ra- tio) below which the PVG is unable to drive subcritical turbulence. In light of this, we use nonlinear simulations to calculate, as a function of three parameters (the perpendicular flow shear, q/ε and the temperature gradient), the surface within that parameter space which divides the regions where turbulence can and cannot be sustained: the zero- turbulence manifold. We are unable to conclude that there is in fact a critical value of q/ε below which PVG-driven turbulence is eliminated. Nevertheless, we demonstrate that at low values of q/ε, the maximum critical temperature gradient that can be reached without generating turbulence (and thus, we infer, the maximum temperature gradient that could be reached in the transport bifurcation) is dramatically increased. Thus, we anticipate that a fusion device for which, across a significant portion of the minor radius, the magnetic shear is low, the ratio q/ε is low and the toroidal flow shear is strong, will achieve high levels of energy confinement and thus high performance.

Turbulence is a major factor limiting the achievement of better tokamak performance as it enhances the transport of particles, momentum and heat which hinders the foremost objective of tokamaks. Hence, understanding and possibly being able to control turbulence in tokamaks is of paramount importance, not to mention our intellectual curiosity of it. We take the first step by making measurements of turbulence using the 2D ($8$ radial $imes$ $4$ poloidal channels) beam emission spectroscopy (BES) system on the Mega Amp Spherical Tokamak (MAST). Measured raw data are statistically processed, generating spatio-temporal correlation functions to obtain the physical characteristics of the turbulence such as spatial and temporal correlation lengths as well as its motion. The reliability of statistical techniques employed in this work is examined by generating and utilizing synthetic 2D BES data. The apparent poloidal velocity of fluctuating density patterns is estimated using the cross-correlation time delay method. The experimental results indicate that the poloidal motion of fluctuating density patterns in the lab frame arises because the patterns are advected by the strong toroidal plasma flows while the patterns are aligned with the background magnetic fields which are not parallel to the flows. Furthermore, various time scales associated with the turbulence are calculated using statistically estimated spatial correlation lengths and correlation times of turbulence. We find that turbulence correlation time, the drift time associated with ion temperature or density gradients, the ion streaming time along the magnetic field line and the magnetic drift time are comparable and possibly scale together suggesting that the turbulence, determined by the local equilibrium, is critically balanced. Finally, we argue that we have produced a critical manifold in the experimentally obtained local equilibrium parameter space separating dominant turbulent transport from a non-turbulent or weakly turbulent state. It shows that the inverse ion-temperature-gradient scale length is correlated inversely with $q/arepsilon$ (safety factor/inverse aspect ratio) and positively with the plasma rotational shear. Practically, this means that we can attain the stiffer ion-temperature-gradient, thus hotter plasma core, without increasing the rotational shear.

This thesis presents a complete theoretical framework for turbulence and transport in tokamak plasmas. The fundamental scale separations present in plasma turbulence are codified as an asymptotic expansion in the ratio of the gyroradius to the equilibrium scale length. Proceeding order-by- order in this expansion, a framework for plasma turbulence is developed. It comprises an instantaneous equilibrium, the fluctuations driven by gra- dients in the equilibrium quantities, and the transport-timescale evolu- tion of mean profiles of these quantities driven by the fluctuations. The equilibrium distribution functions are local Maxwellians with each flux surface rotating toroidally as a rigid body. Large-scale deviations of the distribution function from a Maxwellian are given by neoclassical theory. The fluctuations are determined by the high-flow gyrokinetic equation, from which we derive the governing principle for gyrokinetic turbulence in tokamaks: the conservation and local cascade of free energy. Transport equations for the evolution of the mean density, temperature and flow ve- locity profiles are derived. These transport equations show how the neo- classical corrections and the fluctuations act back upon the mean profiles through fluxes and heating. This framework is further developed by exploiting the scale separation between ions and the electrons. The gyrokinetic equation is expanded in powers of the electron to ion mass ratio, which provides a rigorous method for deriving the electron response to ion-scale turbulence. We prove that such turbulence cannot change the magnetic topology, and ar- gue that, therefore, the magnetic field lies on fluctuating flux surfaces. These flux surfaces are used to construct magnetic coordinates, and in these coordinates a closed system of equations for the electron response is derived. All fast electron timescales have been eliminated from these equations. Simplified transport equations for electrons in this limit are also derived.

The objective of this research is to study various methods for censoring state estimate updates generated from radar measurements. The generated 2-D radar data are sent to a fusion center using the J-Divergence metric as the means to assess the quality of the data. Three different distributed sensor network architectures are considered which include different levels of feedback. The Extended Kalman Filter (EKF) and the Gaussian Particle Filter (GPF) were used in order to test the censoring methods in scenarios which vary in their degrees of non-linearity. A derivation for the direct calculation of the J-Divergence using a particle filter is provided. Results show that state estimate updates can be censored using the J-Divergence as a metric controlled via feedback, with higher J-Divergence thresholds leading to a larger covariance at the fusion center.

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