340 research outputs found

    The Air Warrior\u27s Value of National Security Space

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    The 2001 Report of the Commission to Assess United States National Security Space Management and Organization recommended that U.S. efforts in national security space be elevated to the highest national security priority. With more focused high-level attention on national security space decisions a measure that captures and quantities the value of space capabilities to combat operations professionals is desired. This thesis models what the air warriors desire from space assets in combat. A Value-Focused Thinking (VFT) approach was used to elicit values from air combat experts with operational experience. An initial Gold Standard value model was constructed and validated by air combat experts with recent experience in joint air operations. The strategic objective Leverage National Security Space Capabilities to Enhance Air Combat Operations was decomposed into values which were structured into a hierarchy. Measures and value functions were identified for the bottom-tier values which were weighted locally to assess their relative importance. The research identified measures of merit with thresholds beneath which value at higher levels is eliminated resulting in a multiplicative value function using indicator variables. An additional result is the separation of communication and navigation measures into pre-flight and in- fight components which has not been documented in previous literature

    Simulation of Coastal Inundation Instigated by Storm Surge and River Discharge in the Chesapeake Bay Using Sub-grid Modeling Coupled with Lidar Data

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    Sub-grid modeling is a novel method by which water level elevations on the sub-grid level can be obtained through the combination of water levels and velocities efficiently calculated at the coarse computational grid, the discretized bathymetric depths, and local friction parameters without resorting to solve the full set of equations. Sub-grid technology essentially allows velocity to be determined rationally and efficiently at the sub-grid level. This salient feature enables coastal flooding to be addressed in a single cross-scale model from the ocean to the upstream river channel without overly refining the grid resolution. To this end, high-resolution DEMs will be developed using GIS from Lidar-derived topography for incorporation into a sub-grid model, for research into two case studies related to inundation: (1) The Great Flood of 1936 was utilized as a test for sub-grid modeling in Washington, DC. It demonstrated that the sub-grid model can achieve accurate results upon comparison with NOAA observation data and replicate the results of a likewise-resolution true grid model, indicating that there is minimal loss of quantitative accuracy in the sub-grid approach (R 2 = 99.98). (2) Spatial comparison of GPS wrack line data with model results for 2011 Hurricane Irene demonstrated that sub-grid model results accurately predicted the water level observed at Langley Research Center

    Towards Predicting Street-Level Inundation: using Operational Forecast Modeling Techniques during 2011 Hurricane Irene

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    Storm surge-induced coastal inundation poses numerous personal, commercial, industrial, and sociopolitical challenges for society. Flooding can be caused by the combination of storm surge and river-induced inland flooding in many locations throughout the coastal plain. The cross-disciplinary nature of the hydrodynamics involved (hydraulics, oceanography, and hydrology), coupled with the complexity of the atmospheric forcing, makes a numerical model the best approach for a comprehensive study of the dynamics of coastal inundation. This study builds upon the lessons learned from forecast modeling experiences during 2011 Hurricane Irene in Tidewater Virginia, to ascertain the most effective way to approach predicting street-level inundation. During the storm event, a large-scale ocean model (SCHISM) was provided atmospheric forcing from the National Oceanic and Atmospheric Administrationā€™s Global Forecast System, updated every 6 hours to simulate 9 separate 30-hour simulations, which were provided to emergency managers and the National Weather Service in Wakefield, VA. Forecast water level predictions were evaluated at 5 stations near the Hampton Roads region in the Lower Chesapeake Bay to yield an aggregate RMSE=19.9 cm. To accurately predict street-level inundation, water elevations at key points near the mouths of vulnerable tributaries can be used to drive a separate street-level high-resolution sub-grid model (UnTRIM) to simulate localized flooding events on the scale of 5-meter resolution. To this end, high-resolution Digital Elevation Models including building and roadway infrastructure were developed from Lidar-derived topography for the Hampton Roads Region of Virginia, and used to accurately predict flooding in low-lying areas of the Cities of Norfolk, Portsmouth, and Chesapeake along the Elizabeth and Lafayette Rivers. Additionally, grids were prepared for the City of Virginia Beach along the Lynnhaven River, and along Hampton, York, and Poquoson along the Back River. Tropical storm surge flood heights were validated via temporal comparison with water level observations from NOAA, the USGS, and NASA; aggregated to an average RMSE=0.18 cm. Spatial extent of flooding was evaluated using USGS data retrieved from high water marks and from rapid deployment overland water level gauges during Hurricane Irene to reveal favorable agreement with the modelā€™s inundation predictions

    Moans, Palpable Groin, and Entrapment of Bone: A Case of Malignant Peripheral Nerve Sheath Tumor in an otherwise Healthy Hispanic Male

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    Background: Malignant peripheral nerve sheath tumors (MPNTs) are rare malignant soft tissue sarcomas that have an incidence of about 0.001 %. MPNTs typically occur in individuals who have neurofibromatosis or secondary to radiation therapy and rarely occur sporadically. We present a case of a previously healthy 56-year-old gentleman who was diagnosed with MPNTs. Case: A healthy 56-year-old gentleman presented with worsening LLQ abdominal pain for 6 months. Associated symptoms included bloating, LLE swelling, early satiety for the past 2 months, and a 5-10lb unintentional weight loss. Patient denied recent cough, night sweats, dyspnea, fever, chills, melena or hematochezia. Vitals were WNL. Physical examination revealed a palpable mass on LLQ extending into the groin and edema of the left leg with diminished strength 3/5. CBC and CMP were unremarkable. CT abdomen showed a large necrotic mass in the left retroperitoneum infiltrating along the iliopsoas musculature, extending into the left hip and into the left side of L3, L4, L5 vertebral bodies and through L4 transverse process measuring up to 24.6 x 11.5 x 13 cm. Pathology revealed spindle cell sarcoma composed of moderately atypical, elongated spindle cells positive for vimentin, with loss of H3/K27me3, and negative for SMA, S-100 consistent with MPNSTs. Conclusions: The is a rare case of a sporadic presentation of MPNTs. Treatment depends on the extent of tumor burden and metastatic disease is typically treated with chemotherapy. CT chest showed innumerable pulmonary nodules. Patient is currently being treated with Doxorubicin and Ifosfamide with minimal response

    The Floodwater Depth Estimation Tool (FwDET v2.0) for improved remote sensing analysis of coastal flooding

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    Remote sensing analysis is routinely used to map flooding extent either retrospectively or in near-real time. For flood emergency response, remote-sensing-based flood mapping is highly valuable as it can offer continued observational information about the flood extent over large geographical domains. Information about the floodwater depth across the inundated domain is important for damage assessment, rescue, and prioritizing of relief resource allocation, but cannot be readily estimated from remote sensing analysis. The Floodwater Depth Estimation Tool (FwDET) was developed to augment remote sensing analysis by calculating water depth based solely on an inundation map with an associated digital elevation model (DEM). The tool was shown to be accurate and was used in flood response activations by the Global Flood Partnership. Here we present a new version of the tool, FwDET v2.0, which enables water depth estimation for coastal flooding. FwDET v2.0 features a new flood boundary identification scheme which accounts for the lack of confinement of coastal flood domains at the shoreline. A new algorithm is used to calculate the local floodwater elevation for each cell, which improves the tool\u27s runtime by a factor of 15 and alleviates inaccurate local boundary assignment across permanent water bodies. FwDET v2.0 is evaluated against physically based hydrodynamic simulations in both riverine and coastal case studies. The results show good correspondence, with an average difference of 0.18 and 0.31 m for the coastal (using a 1 m DEM) and riverine (using a 10 m DEM) case studies, respectively. A FwDET v2.0 application of using remote-sensing-derived flood maps is presented for three case studies. These case studies showcase FwDET v2.0 ability to efficiently provide a synoptic assessment of floodwater. Limitations include challenges in obtaining high-resolution DEMs and increases in uncertainty when applied for highly fragmented flood inundation domains

    Anthropocene Sea Level Change: A History of Recent Trends Observed in the U.S. East, Gulf, and West Coast Regions

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    Relative sea level (RSL) observations since 1969 at U.S. tide stations exhibit trends in RSL rise rate and acceleration that vary in response to both global and regional processes. Trend histories display a high degree of similarity between locations in coastal regions that are experiencing similar processes. With the exception of the U.S. Northeast Coast and Alaska,every other coastal location in the continental U.S. has experienced an upturn in RSL rise rate since 2013-2014 despite wide differences in the magnitude and trending direction of RSL acceleration. High RSL acceleration along the U.S. Northeast Coast has trended downward since 2011 while low RSL acceleration along the U.S Southeast Coast has recently trended upward in response to changes likely associated with ocean dynamics and ice sheet loss. RSL change in the sedimentary basins of the central U.S. Gulf Coast region is highly dependent on local rates of vertical land movement (VLM). VLM here varies over relatively short time scales amid changing patterns of subsurface water and hydrocarbons extraction.RSL rise rates of 5 mm/year or more aided by weak acceleration in Louisiana and Texas project a total RSL rise of between 0.4 and 0.5 meters above 1992 MSL by the year 2050; other Gulf and East Coast locations will experience equal or greater rise if upward trends in acceleration continue. Low and mostly downward trends in RSL rise rate at central U.S. West Coast locations have recently reverted to a pattern of upward trends with higher rise rates. Rise rates prior to 2013 appear to have been restrained by deceleration now trending toward acceleration. A combination of tectonic plate convergence and glacial isostatic adjustment makes the non-contiguous U.S. coastal state of Alaska unique with regard to RSL trends. Land emergence, rather than subsidence, produces consistent trends of falling RSL in Alaska

    Management of Wintering Short-Eared Owls at Airports in the Lower Great Lakes Region

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    USDA Wildlife Services airport wildlife biologists have been tasked with reducing the hazards that raptors (including owls) pose to safe aircraft operations at airports and military airfields throughout the USA. A review of available wildlife strike information suggests short-eared owls (Asio flammeus) are frequently struck by aircraft during the winter months at numerous airports within the Lower Great Lakes Region of the United States. Further, this species is listed as ā€˜endangeredā€™ by state fish and wildlife agencies in many states, although not at the federal level. Consequently, there is particular interest in developing non-lethal management tools for reducing the hazards posed by this species. In an effort to gain a better understanding of the efficacy of managing the hazards to aviation posed by short-eared owls, we developed methods to live-capture, mark with USGS aluminum leg bands, and translocate short-eared owls from airport environments (i.e., airfield areas) as part of the overall programs to reduce wildlife hazards to safe aircraft operations at airports. During 2012āˆ’2015, a total of 32 short-eared owls was live-captured, banded, and translocated to release sites approximately 64 to 80 km (40 to 50 miles) away from the airports. Only 1 short-eared owl (3%) was resighted and this bird was found on a different airport from where it had been translocated from. Future research in needed to evaluate the efficacy of translocating wintering short-eared owls from airport environments
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