15,329 research outputs found
Nuclear Disarmament Verification via Resonant Phenomena
Nuclear disarmament treaties are not sufficient in and of themselves to
neutralize the existential threat of the nuclear weapons. Technologies are
necessary for verifying the authenticity of the nuclear warheads undergoing
dismantlement before counting them towards a treaty partner's obligation. This
work presents a novel concept that leverages isotope-specific nuclear resonance
phenomena to authenticate a warhead's fissile components by comparing them to a
previously authenticated template. All information is encrypted in the physical
domain in a manner that amounts to a physical zero-knowledge proof system.
Using Monte Carlo simulations, the system is shown to reveal no isotopic or
geometric information about the weapon, while readily detecting hoaxing
attempts. This nuclear technique can dramatically increase the reach and
trustworthiness of future nuclear disarmament treaties
Analyzing helicopter evasive maneuver effectiveness against rocket-propelled grenades
It has long been acknowledged that military helicopters are vulnerable to ground-launched threats, in particular, the RPG-7 rocket-propelled grenade. Current helicopter threat mitigation strategies rely on a combination of operational tactics and selectively placed armor plating, which can help to mitigate but not entirely remove the threat. However, in recent years, a number of active protection systems designed to protect land-based vehicles from rocket and missile fire have been developed. These systems all use a sensor suite to detect, track, and predict the threat trajectory, which is then employed in the computation of an intercept trajectory for a defensive kill mechanism. Although a complete active protection system in its current form is unsuitable for helicopters, in this paper, it is assumed that the active protection system’s track and threat trajectory prediction subsystem could be used offline as a tool to develop tactics and techniques to counter the threat from rocket-propelled grenade attacks. It is further proposed that such a maneuver can be found by solving a pursuit–evasion differential game. Because the first stage in solving this problem is developing the capability to evaluate the game, nonlinear dynamic and spatial models for a helicopter, RPG-7 round, and gunner, and evasion strategies were developed and integrated into a new simulation engine. Analysis of the results from representative vignettes demonstrates that the simulation yields the value of the engagement pursuit–evasion game. It is also shown that, in the majority of cases, survivability can be significantly improved by performing an appropriate evasive maneuver. Consequently, this simulation may be used as an important tool for both designing and evaluating evasive tactics and is the first step in designing a maneuver-based active protection system, leading to improved rotorcraft survivability
GEMINI: A Generic Multi-Modal Natural Interface Framework for Videogames
In recent years videogame companies have recognized the role of player
engagement as a major factor in user experience and enjoyment. This encouraged
a greater investment in new types of game controllers such as the WiiMote, Rock
Band instruments and the Kinect. However, the native software of these
controllers was not originally designed to be used in other game applications.
This work addresses this issue by building a middleware framework, which maps
body poses or voice commands to actions in any game. This not only warrants a
more natural and customized user-experience but it also defines an
interoperable virtual controller. In this version of the framework, body poses
and voice commands are respectively recognized through the Kinect's built-in
cameras and microphones. The acquired data is then translated into the native
interaction scheme in real time using a lightweight method based on spatial
restrictions. The system is also prepared to use Nintendo's Wiimote as an
auxiliary and unobtrusive gamepad for physically or verbally impractical
commands. System validation was performed by analyzing the performance of
certain tasks and examining user reports. Both confirmed this approach as a
practical and alluring alternative to the game's native interaction scheme. In
sum, this framework provides a game-controlling tool that is totally
customizable and very flexible, thus expanding the market of game consumers.Comment: WorldCIST'13 Internacional Conferenc
Aeronautical Engineering: A special bibliography with indexes, supplement 72, July 1976
This bibliography lists 184 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1976
Human-Machine Collaborative Optimization via Apprenticeship Scheduling
Coordinating agents to complete a set of tasks with intercoupled temporal and
resource constraints is computationally challenging, yet human domain experts
can solve these difficult scheduling problems using paradigms learned through
years of apprenticeship. A process for manually codifying this domain knowledge
within a computational framework is necessary to scale beyond the
``single-expert, single-trainee" apprenticeship model. However, human domain
experts often have difficulty describing their decision-making processes,
causing the codification of this knowledge to become laborious. We propose a
new approach for capturing domain-expert heuristics through a pairwise ranking
formulation. Our approach is model-free and does not require enumerating or
iterating through a large state space. We empirically demonstrate that this
approach accurately learns multifaceted heuristics on a synthetic data set
incorporating job-shop scheduling and vehicle routing problems, as well as on
two real-world data sets consisting of demonstrations of experts solving a
weapon-to-target assignment problem and a hospital resource allocation problem.
We also demonstrate that policies learned from human scheduling demonstration
via apprenticeship learning can substantially improve the efficiency of a
branch-and-bound search for an optimal schedule. We employ this human-machine
collaborative optimization technique on a variant of the weapon-to-target
assignment problem. We demonstrate that this technique generates solutions
substantially superior to those produced by human domain experts at a rate up
to 9.5 times faster than an optimization approach and can be applied to
optimally solve problems twice as complex as those solved by a human
demonstrator.Comment: Portions of this paper were published in the Proceedings of the
International Joint Conference on Artificial Intelligence (IJCAI) in 2016 and
in the Proceedings of Robotics: Science and Systems (RSS) in 2016. The paper
consists of 50 pages with 11 figures and 4 table
Improving rotorcraft survivability to RPG attack using inverse methods
This paper presents the results of a preliminary investigation of optimal threat evasion strategies for improving the survivability of rotorcraft under attack by rocket propelled grenades (RPGs). The basis of this approach is the application of inverse simulation techniques pioneered for simulation of aggressive helicopter manoeuvres to the RPG engagement problem. In this research, improvements in survivability are achieved by computing effective evasive manoeuvres. The first step in this process uses the missile approach warning system camera (MAWS) on the aircraft to provide angular information of the threat. Estimates of the RPG trajectory and impact point are then estimated. For the current flight state an appropriate evasion response is selected then realised via inverse simulation of the platform dynamics. Results are presented for several representative engagements showing the efficacy of the approach
Influence of maneuverability on helicopter combat effectiveness
A computational procedure employing a stochastic learning method in conjunction with dynamic simulation of helicopter flight and weapon system operation was used to derive helicopter maneuvering strategies. The derived strategies maximize either survival or kill probability and are in the form of a feedback control based upon threat visual or warning system cues. Maneuverability parameters implicit in the strategy development include maximum longitudinal acceleration and deceleration, maximum sustained and transient load factor turn rate at forward speed, and maximum pedal turn rate and lateral acceleration at hover. Results are presented in terms of probability of skill for all combat initial conditions for two threat categories
Aeronautical Engineering: A special bibliography with indexes, supplement 51
This bibliography lists 206 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System in November 1974
Integration of tools for the Design and Assessment of High-Performance, Highly Reliable Computing Systems (DAHPHRS), phase 1
Systems for Space Defense Initiative (SDI) space applications typically require both high performance and very high reliability. These requirements present the systems engineer evaluating such systems with the extremely difficult problem of conducting performance and reliability trade-offs over large design spaces. A controlled development process supported by appropriate automated tools must be used to assure that the system will meet design objectives. This report describes an investigation of methods, tools, and techniques necessary to support performance and reliability modeling for SDI systems development. Models of the JPL Hypercubes, the Encore Multimax, and the C.S. Draper Lab Fault-Tolerant Parallel Processor (FTPP) parallel-computing architectures using candidate SDI weapons-to-target assignment algorithms as workloads were built and analyzed as a means of identifying the necessary system models, how the models interact, and what experiments and analyses should be performed. As a result of this effort, weaknesses in the existing methods and tools were revealed and capabilities that will be required for both individual tools and an integrated toolset were identified
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