553 research outputs found

    LVC Interaction within a Mixed Reality Training System

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    The United States military is increasingly pursuing advanced live, virtual, and constructive (LVC) training systems for reduced cost, greater training flexibility, and decreased training times. Combining the advantages of realistic training environments and virtual worlds, mixed reality LVC training systems can enable live and virtual trainee interaction as if co-located. However, LVC interaction in these systems often requires constructing immersive environments, developing hardware for live-virtual interaction, tracking in occluded environments, and an architecture that supports real-time transfer of entity information across many systems. This paper discusses a system that overcomes these challenges to empower LVC interaction in a reconfigurable, mixed reality environment. This system was developed and tested in an immersive, reconfigurable, and mixed reality LVC training system for the dismounted warfighter at ISU, known as the Veldt, to overcome LVC interaction challenges and as a test bed for cuttingedge technology to meet future U.S. Army battlefield requirements. Trainees interact physically in the Veldt and virtually through commercial and developed game engines. Evaluation involving military trained personnel found this system to be effective, immersive, and useful for developing the critical decision-making skills necessary for the battlefield. Procedural terrain modeling, model-matching database techniques, and a central communication server process all live and virtual entity data from system components to create a cohesive virtual world across all distributed simulators and game engines in real-time. This system achieves rare LVC interaction within multiple physical and virtual immersive environments for training in real-time across many distributed systems

    Cellular Automata on Group Sets

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    We introduce and study cellular automata whose cell spaces are left-homogeneous spaces. Examples of left-homogeneous spaces are spheres, Euclidean spaces, as well as hyperbolic spaces acted on by isometries; uniform tilings acted on by symmetries; vertex-transitive graphs, in particular, Cayley graphs, acted on by automorphisms; groups acting on themselves by multiplication; and integer lattices acted on by translations. For such automata and spaces, we prove, in particular, generalisations of topological and uniform variants of the Curtis-Hedlund-Lyndon theorem, of the Tarski-F{\o}lner theorem, and of the Garden-of-Eden theorem on the full shift and certain subshifts. Moreover, we introduce signal machines that can handle accumulations of events and using such machines we present a time-optimal quasi-solution of the firing mob synchronisation problem on finite and connected graphs.Comment: This is my doctoral dissertation. It consists of extended versions of the articles arXiv:1603.07271 [math.GR], arXiv:1603.06460 [math.GR], arXiv:1603.07272 [math.GR], arXiv:1701.02108 [math.GR], arXiv:1706.05827 [math.GR], and arXiv:1706.05893 [cs.FL

    An examination of the resistance training practices within an elite senior English Premier League professional football club.

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    Limited research data is available outlining the resistance training characteristics of elite football players. The aim of the first study (Chapter 3) was to compare approaches to calculating resistance training volume during 4 weeks of pre-season training in 23 English Premier League footballers. Volume was calculated using four different methods of quantification; Repetition volume (RV), Set Volume (SV), Volume Load (VL) and Maximum Dynamic Strength Volume Load (MDSVL). Overall there was a significant difference between resistance training volumes calculated by the different methods used to monitor resistance training load (P < 0.001). More specifically, significant differences were observed between RV and SV methods (P < 0.001), RV and MDSVL (P = 0.001), SV and VL (P = 0.010), SV and MDSVL (P = 0.033) and VL and MDSVL (P = 0.002). Only RV and VL methods were similar in the information they provided on training load (P = 0.411). While the lack of a gold standard measure of volume makes it is unclear which, if any, method represents the most accurate measure of volume the discrepancies between methodological approaches highlight that these different approaches are not directly transferable as strategies to monitor resistance training. The understanding of the differences between each method may therefore enable appropriate, situation specific, approaches to be designed and implemented for both practical and research purposes. The aim of the second study (Chapter 4) was to analyse the resistance training loads completed by an elite professional football team across a competitive season. Resistance training data was collected from 31 elite football players competing in the English Premier League over a 46 week period in the 2012-2013 season. A total of 1685 individual training observations were collected during the pre-season and in-season competition phases, with a median of 42 training sessions per player (range = 9 – 124). Training load data was separated into 7 blocks of 6 weeks for analysis. These periods included pre-season (6 weeks duration) and in-season (40 weeks duration) phases. Set volume was selected as a measure of total volume. Data was analysed using 3 separate linear mixed modelling analysis using the statistical software package R (Version 3.0.1). Weekly resistance training frequency (mean±SD) ranged from 1±1 to 2±1 sessions per week during the pre and in season phases. Significant differences in session frequency were seen between weeks 1-6 and weeks 7-12 (pre-season) (P ˂ 0.05), weeks 7-12 and weeks 13-18 (P ˂ 0.05), and weeks 7-12 and weeks 37-42 (P ˂ 0.05). Mean weekly training volume ranged from 18±16 to 30±24 sets.wk-1. The total training volume demonstrates a clear minimum during weeks 7-12. Significant differences in total training volume were also observed between weeks 1-6 and weeks 7-12 (pre-season) (P ˂ 0.01), weeks 7-12 and weeks 13-18 (P ˂ 0.05), and weeks 7-12 and weeks 19-24 (P ˂ 0.05). There was no significant difference in training intensity between weeks 1-6 (pre-season) and weeks 7-12. Training intensity during weeks 1-6 however was significantly lower than during weeks 13-18 (P ˂ 0.05), 19-24 (P ˂ 0.01), 25-30 (P ˂ 0.01), 31-36 (P ˂ 0.05), and 37-42 (P ˂ 0.01). Training intensity during weeks 7-12 was also significantly lower than during weeks 13-18 (P ˂ 0.01), 19-24 (P ˂ 0.05), 25-30 (P ˂ 0.05), 31-36 (P ˂ 0.05), and 37-42 (P ˂ 0.001). The findings would suggest that resistance training loading is limited during different periods of the season. This is predominantly as a consequence of low training frequency, potentially due to a high prevalence of competitive fixtures. The aim of the third study (Chapter 5) was to attempt to quantify the impact of resistance training completed by players, through evaluating the change in the lower body power outputs of an elite professional football team across a competitive season. Resistance training data was collected from 22 elite football players competing in the English Premier League over a 38 week period. A total of 246 individual power output observations were collected during the in-season competition phase. Power output of the lower body was assessed using a pneumatic resistance leg press machine with software and digital display (Keiser Sports Health Equipment Inc., Fresno, Ca). Data was analysed by means of linear mixed modelling analysis using the statistical software package R (Version 3.0.1). Power outputs ranged from 2200W to 4078W with a mean value of 3022±374W. Linear mixed effects show a significant effect of week on power output across the season (coefficient= 7.76W, p=0.0132). Specifically, when accounting for within player effects, power output increased 7.76W per week during the season. Individual weekly power coefficients ranged from +39.9W to -18.13W per week, thus indicating that the trend for increased power output across the season is not uniform for all the players. These data may suggest that lower body power performance is maintained or minimally enhanced over the course of a full competitive season in elite football players. Combined with the training load data previously examined in this thesis it can be concluded that whilst one resistance training session per week may be sufficient to avoid in season de-training or minimally improve power performance in elite football players, a frequency of two sessions per week may be necessary to obtain significant performance enhancements. In our fourth study (Chapter 6) we provide two case studies that outline and evaluate a structured approach to increasing resistance training loading with the primary goal of developing strength and power during the competitive season in elite football players. The purpose of our initial case was to examine a resistance training programme to enhance strength and power performance, alongside body composition during a period of rehabilitation from injury. The study intervention commenced following two weeks of recovery following the “Laterjet” surgical procedure. Initial assessments were performed for body composition via dual-energy x-ray absorptiometry (DXA) (QDR Series Discovery A, Hologic Inc., Bedford, MA) and lower body power output via using a pneumatic resistance leg press machine with software and digital display (Keiser Sports Health Equipment Inc., Fresno, Ca). Assessments were repeated 8 weeks post-surgery, i.e. following 6 weeks of resistance training. The six-week intervention consisted of three strength training sessions per week for the initial 3 weeks, followed by 2 sessions per week for the subsequent 3 weeks. Training volume (number of sets) equalled a total of 20 sets total per session. Total increase in body mass over the intervention period equated to 5.4kg, of which 4.2 kg increase in lean mass and a 1.3 kg increase in fat mass. Peak power output increased by 21%. Power to weight ratio also increased by 4.4 %. These data illustrate that it is possible to increase physical performance when rapid short-term increase in resistance training load is completed. The purpose of our second case was to examine a resistance training programme to enhance both strength and power performance parameters during a full competitive season. The player plays as a goalkeeper, regularly playing for his club 1st team. Prior to the onset of this case study this player did not present with any current injuries. This season long intervention consisted of two phases of training. Phase 1 was 16 weeks in duration and represented the beginning to the mid-point of the season. During this phase the goal was to gradually and safely increase resistance training loading. Phase 2 was 20 weeks in duration and represented the mid-point to the end of the season. This phase represented a period of consistent high loading following the initial systematic increase in these variables. Assessment data was collected at the beginning, mid-point and end of the 2013-14 season. The player was first assessed for body composition via DXA (QDR Series Discovery A, Hologic Inc., Bedford, MA). Secondly, lower body power output was assessed using a pneumatic resistance leg press machine with software and digital display (Keiser Sports Health Equipment Inc., Fresno, Ca). Finally, the player’s upper body strength was assessed via 6 repetition maximum assessments of the dumbell bench press and prone row. The player completed a mean weekly volume of 41±24 sets per week and a mean frequency of 2±1 sessions per week for the initial phase of the study. The player completed a greater mean weekly volume in the later phase of the season compared to the initial training period (65±28 set per week vs. 41±24 sets per week in the initial phase of the season). A greater mean session frequency was also associated with the second training phase (3±1 vs. 2±1 session per week). There was a total decrease in body mass over the initial intervention period of 4kg, of which 2.7kg decrease in fat mass and a further 0.9 kg decrease in lean mass. Over the second phase of the intervention there was a total increase in body mass of 1.2kg, of which 2.4kg increase in lean mass and 1.2kg decrease in fat mass. During the initial phase of training peak power output increased by 25%, whilst power to weight ratio increased by 30%. During the later phase peak power output increased by a further 9% whilst the power to weight ratio increased by a further 10%. Upper body pressing (Dumbell Bench press) and upper body pulling (Dumbell Prone pull) strength was also increased by 14% and 21% respectively during the initial phase and a further 19% and 24% respectively during the later phase of the season. Although it is difficult to compare the findings of these individual cases to broader outcomes associated with a squad, in general, this data does seem to indicate that if resistance training programme variables are manipulated to increase training load it is possible to successfully increase physical performance parameters in both short, focused interventions and more long term, gradual approaches

    Autonomous Weapon Systems: A Brief Survey of Developmental, Operational, Legal, and Ethical Issues

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    What does the Department of Defense hope to gain from the use of autonomous weapon systems (AWS)? This Letort Paper explores a diverse set of complex issues related to the developmental, operational, legal, and ethical aspects of AWS. It explores the recent history of the development and integration of autonomous and semi-autonomous systems into traditional military operations. It examines anticipated expansion of these roles in the near future as well as outlines international efforts to provide a context for the use of the systems by the United States. As these topics are well-documented in many sources, this Paper serves as a primer for current and future AWS operations to provide senior policymakers, decisionmakers, military leaders, and their respective staffs an overall appreciation of existing capabilities and the challenges, opportunities, and risks associated with the use of AWS across the range of military operations. Emphasis is added to missions and systems that include the use of deadly force.https://press.armywarcollege.edu/monographs/1303/thumbnail.jp

    The Parthenon, October 7, 2014

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    The Parthenon, Marshall University’s student newspaper, is published by students Monday through Friday during the regular semester and weekly Thursday during the summer. The editorial staff is responsible for the news and the editorial content

    Bardian, Vol. 2, No. 2, New Series (March 12, 1945)

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    https://digitalcommons.bard.edu/bardian/1096/thumbnail.jp

    Archives of Memory: A Soldier Recalls World War II

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    “Tell me about the war”—these words launched a ten-year project in oral history by a husband-and-wife team. Howard Hoffman fought in World War II from Cassino to the Elbe as a mortar crewman and a forward observer. His war experiences are of intrinsic interest to readers who seek a foot soldier’s view of those historic events. But the principal purpose of this study was to explore the bounds of memory, to gauge its accuracy and its stability over time, and to determine the effects of various efforts to enhance it. Alice Hoffman, a historian, initiated the study because she recognized the critical role of memory in gathering oral history; Howard Hoffman, the subject, is an experimental psychologist. Alice’s tape-recorded interviews with her husband over a period of ten years are the basic material of the study, which compares the events as recounted in the first phase of the interviews with later accounts of the same experiences and with the written records of his company as well as the memories of fellow soldiers and the evidence of photographs and other documents. This engrossing story of World War II breaks new ground for practitioners of oral history. The Hoffmans’ findings indicate that a subset of human memory exists that is so permanent and resistant to change that it can properly be labeled “archival”. In addition to describing some of the circumstances under which archival memories are formed, the Hoffmans describe the conditions that were found to influence their storage and retrieval. If you are an oral historian who enjoys war stories, you will take up this book without hesitation; if you don’t enjoy them, you should persist anyway. —Oral History Review A significant work in oral history. This book will help those who collect and use oral histories understand how and what people remember. —American Historical Reviewhttps://uknowledge.uky.edu/upk_military_history/1004/thumbnail.jp
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