Scatter profiling and the extent of product ion angular scattering in some non-dissociative polyatomic collisions of kiloelectronvolt energy ions with stationary target-gas particles

This article proposes an impact-time-control guidance law that can keep a non-maneuvering moving target in the seeker’s field of view (FOV). For a moving target, the missile calculates a predicted intercept point (PIP), designates the PIP as a new virtual stationary target, and flies to the PIP at the desired impact time. The main contribution of the article is that the guidance law is designed to always lock onto the moving target by adjusting the guidance gain. The guidance law for the purpose is based on the backstepping control technique and designed to regulate the defined impact time error. In this procedure, the desired look angle, which is a virtual control, is designed not to violate the FOV limit, and the actual look angle of the missile is kept within the FOV by tracking the desired look angle. To validate the performance of the guidance law, numerical simulation is conducted with different impact times. The result shows that the proposed guidance law intercepts the moving target at the desired impact time maintaining the target lock-on condition.

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Angular scattering and internal energy deposition in kiloelectronvolt collision activated decomposition reactions of some low mass cations

International Journal of Mass Spectrometry and Ion Processes ◽

10.1016/0168-1176(91)87012-p ◽

1991 ◽

Vol 105 (3) ◽

pp. 191-213 ◽

Cited By ~ 4

Author(s):

C.J. Reid

Keyword(s):

Internal Energy ◽

Energy Deposition ◽

Decomposition Reactions ◽

Internal Energy Deposition ◽

Angular Scattering ◽

Low Mass

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Differentiating Laparoscopic Skills of Trainees with Computer Vision Based Metrics

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/1071181321651263 ◽

2021 ◽

Vol 65 (1) ◽

pp. 304-308

Author(s):

Shiyu Deng ◽

Chaitanya Kulkarni ◽

Tianzi Wang ◽

Jacob Hartman-Kenzler ◽

Laura E. Barnes ◽

...

Keyword(s):

Computer Vision ◽

Transfer Task ◽

High Sensitivity ◽

Video Data ◽

Machine Learning Algorithms ◽

Fixation Rate ◽

Skill Levels ◽

Stationary Target ◽

Practice Trials ◽

Context Dependent

Context dependent gaze metrics, derived from eye movements explicitly associated with how a task is being performed, are particularly useful for formative assessment that includes feedback on specific behavioral adjustments for skill acquisitions. In laparoscopic surgery, context dependent gaze metrics are under investigated and commonly derived by either qualitatively inspecting the videos frame by frame or mapping the fixations onto a static surgical task field. This study collected eye-tracking and video data from 13 trainees practicing the peg transfer task. Machine learning algorithms in computer vision were employed to derive metrics of tool speed, fixation rate on (moving or stationary) target objects, and fixation rate on tool-object combination. Preliminary results from a clustering analysis on the measurements from 499 practice trials indicated that the metrics were able to differentiate three skill levels amongst the trainees, suggesting high sensitivity and potential of context dependent gaze metrics for surgical assessment.

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