310 research outputs found

    Navigating the Skies: An Exploration of Stakeholder Perspectives on Rules for Orbital Traffic Coordination using Grounded Theory and Case Study Research Methodologies

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    This dissertation explored standards, rules, or regulations ( rules ) of orbital traffic coordination to reduce the risk of collisions in space between active space objects. The research questions explored topics associated with areas for potential implementation of rules include maneuvering capabilities, liability and insurance, zoning, right-of-way, and tracking of objects in space. The researcher utilized an exploratory qualitative research method because of the developing field of study and a growing domain for potential regulation. The research design is a mixture of a case study for bounding and structuring the data collection and grounded theory for a rigorous and well-defined analysis approach. The primary data source is semi-structured interviews used to explore the perspectives of three stakeholder groups with a vested interest in space traffic management. The three groups are space industry, space insurance industry, and space law and policy experts. Amongst the three groups, 19 interviews were conducted. The data were analyzed to summarize and compare the different perspectives of each group and across the groups. From the summarized perspectives, the intent was to recommend a set of rules, but participants offered few specific rules. Instead, the dissertation’s results present shared considerations across the six research questions to provide the current state of thinking across the community. Results from this dissertation will provide valuable insight to policymakers beyond feedback generally received during comment periods associated with federal rulemaking. National space traffic management legal frameworks need to harmonize globally to optimize space transportation operations and practices. This dissertation contributes to a larger global effort to standardize and solidify rules defining interactions between space operators by capturing the perspectives of experts primarily in and concerning the United States

    Summer 2023 Full Issue

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    “Corpses in the Grass”: strategic culture and combat effectiveness in the Pacific War; a case study of the U.S. Seventh Infantry Division

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    Rather than accepting the premise that American industrial capacity and the sheer quantitative advantage that it produced were the only reasons that the U.S. was able to prevail over its qualitatively superior foes during the Second World War, I will demonstrate through the four different Pacific theater campaigns of the 7th Infantry Division the decisive importance of willpower and the less explored influence of strategic culture on the outcome of the war. I will challenge the theory of the supposedly inexorable triumph of American military mass as opposed to its superior combat effectiveness through a case study exploring the performance of the 7th U.S. Infantry Division in the Pacific. This case study contains two principal elements: the first is an analysis of the battles of Attu, Kwajalein, Leyte, and Okinawa and the second is a comparison of the strategic/tactical cultures of Japan and the United States and how they contributed to and influenced the relative combat effectiveness of the opposing forces. My hypothesis is that the 7th Division was comparatively more combat-efficient than its Japanese opponents because of an American “tactical culture” characterized by superior leadership that embodied adaptability and flexibility, informed by continuous learning that resulted in realistic training and highly effective tactical performance. The inspiration for this thesis began with the author’s Master of Arts dissertation, “Hell in the Mist: The Seventh Infantry Division and the Battle of Attu” completed for Southern New Hampshire University in 2015. Significant portions of this thesis borrow from and incorporate elements of that study. By extending the combat effectiveness debate from the European theater to the Pacific theater, I challenge the deterministic assumptions made by other historians about American industrial superiority over Japan by taking a cultural approach to provide new possible explanations of historical events. In this way, the competing hypotheses of how and why one force was more combat effective can be further explored. I will contrast and compare the American and Japanese strategic, operational, tactical, and human dimensions of the Pacific War

    Operational research:methods and applications

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    Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order

    Cyber-Human Systems, Space Technologies, and Threats

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    CYBER-HUMAN SYSTEMS, SPACE TECHNOLOGIES, AND THREATS is our eighth textbook in a series covering the world of UASs / CUAS/ UUVs / SPACE. Other textbooks in our series are Space Systems Emerging Technologies and Operations; Drone Delivery of CBNRECy – DEW Weapons: Emerging Threats of Mini-Weapons of Mass Destruction and Disruption (WMDD); Disruptive Technologies with applications in Airline, Marine, Defense Industries; Unmanned Vehicle Systems & Operations On Air, Sea, Land; Counter Unmanned Aircraft Systems Technologies and Operations; Unmanned Aircraft Systems in the Cyber Domain: Protecting USA’s Advanced Air Assets, 2nd edition; and Unmanned Aircraft Systems (UAS) in the Cyber Domain Protecting USA’s Advanced Air Assets, 1st edition. Our previous seven titles have received considerable global recognition in the field. (Nichols & Carter, 2022) (Nichols, et al., 2021) (Nichols R. K., et al., 2020) (Nichols R. , et al., 2020) (Nichols R. , et al., 2019) (Nichols R. K., 2018) (Nichols R. K., et al., 2022)https://newprairiepress.org/ebooks/1052/thumbnail.jp

    WiFi-Based Human Activity Recognition Using Attention-Based BiLSTM

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    Recently, significant efforts have been made to explore human activity recognition (HAR) techniques that use information gathered by existing indoor wireless infrastructures through WiFi signals without demanding the monitored subject to carry a dedicated device. The key intuition is that different activities introduce different multi-paths in WiFi signals and generate different patterns in the time series of channel state information (CSI). In this paper, we propose and evaluate a full pipeline for a CSI-based human activity recognition framework for 12 activities in three different spatial environments using two deep learning models: ABiLSTM and CNN-ABiLSTM. Evaluation experiments have demonstrated that the proposed models outperform state-of-the-art models. Also, the experiments show that the proposed models can be applied to other environments with different configurations, albeit with some caveats. The proposed ABiLSTM model achieves an overall accuracy of 94.03%, 91.96%, and 92.59% across the 3 target environments. While the proposed CNN-ABiLSTM model reaches an accuracy of 98.54%, 94.25% and 95.09% across those same environments

    Missile Modeling and Simulation of Nominal and Abnormal Scenarios Resulting from External Damage

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    This thesis presents the development of a six-degree-of-freedom flight simulation environment for missiles and the application thereof to investigate the flight performance of missiles when exposed to external damage. The simulation environment was designed to provide a realistic representation of missile flight dynamics including aerodynamic effects, flight control systems, and self-guidance. The simulation environment was designed to be modular, expandable, and include realistic models of external damage to the missile body obtained by adversarial counteraction. The primary objective of this research was to examine missile flight performance when subjected to unspecified external damage, including changes in trajectory, stability, and controllability, and to provide a basis for the future development of fault tolerant control laws to improve target tracking and overall flight performance when experiencing abnormal conditions. To accomplish this, a variety of scenarios were developed to simulate damage to different parts of the missile, such as the fuselage, wings, and control surfaces. Three types of damage are considered: arbitrary failures which affect the major overall missile dynamic force and moment coefficients, structural failures including wings and fin breakage, and stuck fin failures where a given fin is arbitrarily fixed to a specified deflection. The missile behavior in response to these scenarios was analyzed and compared to the baseline behavior of an undamaged missile. The results of this research demonstrate how simulated missiles behave during flight, under both nominal and abnormal scenarios resulting from external damage. The simulation environment is shown to be a useful tool in examining the performance of missiles under real-world scenarios, such as during combat, in the event of an accident, or when exposed to other adversarial counteractions. This is done by producing envelopes for mission success for each tested scenario and analyzing the results. The results of this research can be used to assist in and improve the design and performance of missiles and enhance their survivability in the field. These results can also be used to determine the amount of damage necessary to prevent a given missile from reaching its target
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