3,644 research outputs found
Of Hollywood and History: The Columbus Movies of '92
Photograph of Progressive County Music singer Larry Gatlin, performing at the 48 Hours in Atoka Concert, Atoka, OK. Photo by Fred W. Marvel, August 1975
"Saving the West from the Pope": Anti-Catholic Propaganda and the Settlement of the Mississippi River Valley
Investigation of turbulence effect on the free space optical link for ground-to-train communications
There is a growing demand for high mobility and ultrafast internet/data services which drives the motivation for free space optical (FSO) communications for high speed trains. Here we present an FSO link for the ground-to-train communications, which consists of optical transceivers positioned alongside the track and on the roof of the train. When the train moves at a high speed, the airwave induced turbulence degrades the FSO link performance. In this paper the effect of turbulence is experimentally investigated and compared with the case of no turbulence
Capabilities of Conductive Thread Twisted-and-Coiled Actuators as Sarcomeres
Twisted-and-coiled actuators (TCAs) have shown great potential as an artificial muscle for robotics in terms of material cost and production expenses. However, the power-to-force efficiency of these artificial muscles falls short of biological muscles. Soft robotics takes inspiration from biological organisms for more natural movement, and biological mimicry helps increase the efficiency of robotics. Taking inspiration from how sarcomeres are structured in natural muscles, improvements in the energy efficiency of artificial muscles are possible. In this paper, an experiment was designed to analyze the effects on the efficiency of emulating biological sarcomere structures in artificial muscles. Specifically, this experiment used a load cell to capture and compare data between conventional and biological-emulating applications of TCAs under concentric contraction conditions. The experiment used silver-plated sewing thread to fabricate TCAs. While many works have attempted to increase efficiency by changing the material of the TCA, we show that it is also possible to increase efficiency by changing the structure of the TCAs, and the electrical circuit that connects the TCAs. The resulting TCA was approximately seven times as effective as its unchanged counterpart. Additionally, for the same amount of input power, the changed TCA’s contraction is approximately three times as much force as the unchanged TCA. Optimizing the resulting efficiency of this new TCA requires further study of the thermoelectrical properties of the material used for the TCA. Nevertheless, the increased efficiency of changing the structure of the TCA to mimic biological muscles may be worth a new endeavor
Towards Informing an Intuitive Mission Planning Interface for Autonomous Multi-Asset Teams via Image Descriptions
Establishing a basis for certification of autonomous systems using trust and trustworthiness is the focus of Autonomy Teaming and TRAjectories for Complex Trusted Operational Reliability (ATTRACTOR). The Human-Machine Interface (HMI) team is working to capture and utilize the multitude of ways in which humans are already comfortable communicating mission goals and translate that into an intuitive mission planning interface. Several input/output modalities (speech/audio, typing/text, touch, and gesture) are being considered and investigated in the context human-machine teaming for the ATTRACTOR design reference mission (DRM) of Search and Rescue or (more generally) intelligence, surveillance, and reconnaissance (ISR). The first of these investigations, the Human Informed Natural-language GANs Evaluation (HINGE) data collection effort, is aimed at building an image description database to train a Generative Adversarial Network (GAN). In addition to building an image description database, the HMI team was interested if, and how, modality (spoken vs. written) affects different aspects of the image description given. The results will be analyzed to better inform the designing of an interface for mission planning
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